chlorpromazine (Rx)

Schizophrenia, Psychotic Disorders

PO: 30-75 mg/day divided q6-12hr initially; maintenance: usually 200 mg/day (up to 800 mg/day in some patients; some patients may require 1-2 g/day)

IV/IM: 25 mg initially, followed PRN with 25-50 mg after 1-4 hours, then increased to maximum of 400 mg q4-6hr until patient is controlled; usual dosage 300-800 mg/day

Nausea & Vomiting

PO: 10-25 mg q4-6hr PRN

IV/IM: 25-50 mg q4-6hr PRN

Preoperative Apprehension

25-50 mg PO 2-3 hours before surgery

12.5-25 mg IM 1-2 hours before surgery

Intraoperative Sedation

12.5 IM q30min or 2 mg IV q2min; total dose not to exceed 25 mg

Intractable Hiccups

25-50 mg PO q6-8hr; if hiccups persist after 2-3 days of oral therapy, administer 25-50 mg IM q3-4hr; if symptoms persist, administer 25-50 mg by slow IV infusion with patient lying flat in bed; monitor BP

Acute Intermittent Porphyria

25-50 mg PO q6-8hr

Migraine Headache (Off-label)

5-50 mg IV as single dose

Behavioral Disorders, Hyperactivity

<6 months: Safety and efficacy not established

≥6 months: 50-100 mg/day PO/IM; 200 mg/day or more may be necessary for older hospitalized patients; for outpatients, may administer 0.55 mg/kg q4-6hr PRN  

Nausea & Vomiting

<6 months: Safety and efficacy not established

≥6 months: 0.5-1 mg/kg PO/IM q6-8hr PRN  

Preoperative Apprehension

<6 months: Safety and efficacy not established

≥6 months: 0.55 mg/kg PO/IM 1-2 hours before surgery  

Contraindicated (11)

• amisulpride

  amisulpride, chlorpromazine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndrome.

• disopyramide

  chlorpromazine and disopyramide both increase QTc interval. Contraindicated.

• eliglustat

  chlorpromazine increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.

• ibutilide

  chlorpromazine and ibutilide both increase QTc interval. Contraindicated.

• indapamide

  chlorpromazine and indapamide both increase QTc interval. Contraindicated.

• metrizamide

  chlorpromazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.

• pentamidine

  chlorpromazine and pentamidine both increase QTc interval. Contraindicated.

• pimozide

  chlorpromazine and pimozide both increase QTc interval. Contraindicated.

• procainamide

  chlorpromazine and procainamide both increase QTc interval. Contraindicated.

• quinidine

  chlorpromazine and quinidine both increase QTc interval. Contraindicated.

• sotalol

  chlorpromazine and sotalol both increase QTc interval. Contraindicated.

Serious - Use Alternative (145)

• adagrasib

  adagrasib, chlorpromazine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Each drug prolongs the QTc interval, which may increased the risk of Torsade de pointes, other serious arryhthmias, and sudden death. If coadministration unavoidable, more frequent monitoring is recommended for such patients.

• alfuzosin

  alfuzosin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• aminolevulinic acid oral

  aminolevulinic acid oral, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid administering other phototoxic drugs with aminolevulinic acid oral for 24 hr during perioperative period.

• aminolevulinic acid topical

  chlorpromazine increases toxicity of aminolevulinic acid topical by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of photosensitizing drugs may enhance the phototoxic reaction to photodynamic therapy with aminolevulinic acid.

• amiodarone

  chlorpromazine and amiodarone both increase QTc interval. Avoid or Use Alternate Drug.

• amisulpride

  chlorpromazine and amisulpride both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amitriptyline

  chlorpromazine and amitriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• amoxapine

  chlorpromazine and amoxapine both increase QTc interval. Avoid or Use Alternate Drug.

• anagrelide

  anagrelide and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• apomorphine

  chlorpromazine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.
  
  apomorphine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• aripiprazole

  aripiprazole and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• arsenic trioxide

  chlorpromazine and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether

  artemether and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  chlorpromazine and artemether/lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  asenapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine transdermal

  asenapine transdermal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• atomoxetine

  atomoxetine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• benzhydrocodone/acetaminophen

  benzhydrocodone/acetaminophen, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).
  
  benzhydrocodone/acetaminophen and chlorpromazine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

• bromocriptine

  chlorpromazine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• buprenorphine

  buprenorphine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  buprenorphine buccal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  buprenorphine subdermal implant and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.
  
  buprenorphine subdermal implant and chlorpromazine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

• buprenorphine transdermal

  buprenorphine transdermal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  buprenorphine, long-acting injection and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• bupropion

  chlorpromazine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible.

• cabergoline

  chlorpromazine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• calcium/magnesium/potassium/sodium oxybates

  chlorpromazine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• carvedilol

  carvedilol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• ceritinib

  ceritinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• chloroquine

  chloroquine increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• clarithromycin

  chlorpromazine and clarithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• clomipramine

  chlorpromazine and clomipramine both increase QTc interval. Avoid or Use Alternate Drug.

• clozapine

  clozapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• dacomitinib

  dacomitinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• degarelix

  degarelix and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• desflurane

  desflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• desipramine

  chlorpromazine and desipramine both increase QTc interval. Avoid or Use Alternate Drug.

• dofetilide

  chlorpromazine and dofetilide both increase QTc interval. Avoid or Use Alternate Drug.
  
  dofetilide increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• donepezil

  donepezil and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• dopamine

  chlorpromazine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• dosulepin

  chlorpromazine and dosulepin both increase QTc interval. Avoid or Use Alternate Drug.

• doxepin

  chlorpromazine and doxepin both increase QTc interval. Avoid or Use Alternate Drug.

• dronedarone

  chlorpromazine and dronedarone both increase QTc interval. Avoid or Use Alternate Drug.

• droperidol

  chlorpromazine and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• efavirenz

  efavirenz and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• eliglustat

  eliglustat and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• encorafenib

  encorafenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  chlorpromazine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine

  epinephrine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine racemic

  epinephrine racemic and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• eribulin

  eribulin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

• erythromycin base

  chlorpromazine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  chlorpromazine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  chlorpromazine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  chlorpromazine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• escitalopram

  escitalopram increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• fentanyl

  fentanyl, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  fentanyl intranasal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  fentanyl transdermal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  fentanyl transmucosal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fexinidazole

  fexinidazole and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels and/or prolong QT interval.

• fingolimod

  fingolimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• fluconazole

  chlorpromazine and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fluoxetine

  fluoxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• fluphenazine

  chlorpromazine and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug.

• formoterol

  chlorpromazine and formoterol both increase QTc interval. Avoid or Use Alternate Drug.

• gadobenate

  gadobenate and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• gemifloxacin

  gemifloxacin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• gilteritinib

  gilteritinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• givosiran

  givosiran will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• glasdegib

  chlorpromazine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• granisetron

  granisetron and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• haloperidol

  chlorpromazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.

• hydrocodone

  hydrocodone, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• hydroxychloroquine sulfate

  hydroxychloroquine sulfate and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• imipramine

  chlorpromazine and imipramine both increase QTc interval. Avoid or Use Alternate Drug.

• inotuzumab

  inotuzumab and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

• isoflurane

  isoflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• ivosidenib

  ivosidenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

• ketoconazole

  chlorpromazine and ketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• lefamulin

  lefamulin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• levodopa

  chlorpromazine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  chlorpromazine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Phenothiazine/1st generation antipsychotics inhibit dopamine D2 receptors in varying degrees.

• levoketoconazole

  chlorpromazine and levoketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• lisuride

  chlorpromazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lithium

  lithium and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• lofepramine

  chlorpromazine and lofepramine both increase QTc interval. Avoid or Use Alternate Drug.

• lumefantrine

  chlorpromazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• macimorelin

  macimorelin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

• maprotiline

  chlorpromazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.

• methyl aminolevulinate

  chlorpromazine, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.

• methyldopa

  chlorpromazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• metoclopramide intranasal

  chlorpromazine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  chlorpromazine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• metoprolol

  metoprolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• mirtazapine

  mirtazapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• mobocertinib

  mobocertinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• moxifloxacin

  chlorpromazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• nilotinib

  chlorpromazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.

• nortriptyline

  chlorpromazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide

  chlorpromazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide (Antidote)

  chlorpromazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.

• olanzapine

  olanzapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• olopatadine intranasal

  chlorpromazine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• ondansetron

  chlorpromazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

• oxaliplatin

  oxaliplatin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• panobinostat

  chlorpromazine and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

• paroxetine

  paroxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• perphenazine

  chlorpromazine and perphenazine both increase QTc interval. Avoid or Use Alternate Drug.

• pexidartinib

  chlorpromazine and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.

• pitolisant

  chlorpromazine and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

• ponesimod

  ponesimod, chlorpromazine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Generally, should not be initiated in patients who are concurrently taking QT prolonging drugs with known arrhythmogenic properties, such as HR-lowering calcium channel blockers (eg, verapamil, diltiazem).

• pramipexole

  chlorpromazine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• primaquine

  primaquine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• prochlorperazine

  chlorpromazine and prochlorperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promazine

  chlorpromazine and promazine both increase QTc interval. Avoid or Use Alternate Drug.

• promethazine

  chlorpromazine and promethazine both increase QTc interval. Avoid or Use Alternate Drug.

• propafenone

  propafenone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• propranolol

  propranolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• protriptyline

  chlorpromazine and protriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• quinidine

  quinidine, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive cardiac effects.

• ribociclib

  ribociclib increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• ropinirole

  chlorpromazine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• selinexor

  selinexor, chlorpromazine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• sertraline

  sertraline and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• sevoflurane

  sevoflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• siponimod

  siponimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• sodium oxybate

  chlorpromazine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• solifenacin

  solifenacin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• sunitinib

  sunitinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• tacrolimus

  tacrolimus and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• tetrabenazine

  tetrabenazine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• thioridazine

  chlorpromazine and thioridazine both increase QTc interval. Avoid or Use Alternate Drug.

• trazodone

  chlorpromazine and trazodone both increase QTc interval. Avoid or Use Alternate Drug.

• tretinoin

  chlorpromazine, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• tretinoin topical

  chlorpromazine, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• trifluoperazine

  chlorpromazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• trimipramine

  chlorpromazine and trimipramine both increase QTc interval. Avoid or Use Alternate Drug.

• umeclidinium bromide/vilanterol inhaled

  chlorpromazine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vandetanib

  chlorpromazine, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.

• vemurafenib

  vemurafenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended.

• vilanterol/fluticasone furoate inhaled

  chlorpromazine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• vorinostat

  vorinostat and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• vortioxetine

  chlorpromazine increases levels of vortioxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Decrease vortioxetine dose by 50% when coadministered with strong CYP2D6 inhibitors.

• yohimbe

  yohimbe decreases effects of chlorpromazine by pharmacodynamic antagonism. Contraindicated.

• ziprasidone

  chlorpromazine and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (330)

• abiraterone

  abiraterone increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

• abobotulinumtoxinA

  abobotulinumtoxinA increases effects of chlorpromazine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• aclidinium

  aclidinium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• acrivastine

  acrivastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• albiglutide

  chlorpromazine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• albuterol

  chlorpromazine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  albuterol and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• alfentanil

  alfentanil and chlorpromazine both increase sedation. Use Caution/Monitor.

• alfuzosin

  chlorpromazine and alfuzosin both increase QTc interval. Use Caution/Monitor.

• alprazolam

  alprazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• amifampridine

  chlorpromazine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• amitriptyline

  chlorpromazine and amitriptyline both increase sedation. Use Caution/Monitor.

• amobarbital

  amobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• amoxapine

  chlorpromazine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and amoxapine both increase sedation. Use Caution/Monitor.

• anticholinergic/sedative combos

  anticholinergic/sedative combos decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

  chlorpromazine and apomorphine both increase sedation. Use Caution/Monitor.

• arformoterol

  chlorpromazine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  arformoterol and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• aripiprazole

  aripiprazole and chlorpromazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and chlorpromazine both increase sedation. Use Caution/Monitor.

• armodafinil

  chlorpromazine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• artemether/lumefantrine

  artemether/lumefantrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• asenapine

  asenapine and chlorpromazine both increase sedation. Use Caution/Monitor.

• asenapine transdermal

  asenapine transdermal and chlorpromazine both increase sedation. Use Caution/Monitor.

• atracurium

  atracurium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  atropine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine IV/IM

  chlorpromazine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.

• avapritinib

  avapritinib and chlorpromazine both increase sedation. Use Caution/Monitor.

• azelastine

  azelastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• azithromycin

  chlorpromazine and azithromycin both increase QTc interval. Use Caution/Monitor.

• baclofen

  baclofen and chlorpromazine both increase sedation. Use Caution/Monitor.

• bedaquiline

  chlorpromazine and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

• belladonna alkaloids

  belladonna alkaloids decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  belladonna and opium and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  belladonna and opium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• benperidol

  benperidol and chlorpromazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and chlorpromazine both increase sedation. Use Caution/Monitor.

• benzphetamine

  chlorpromazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• benztropine

  chlorpromazine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• bosutinib

  bosutinib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• brexanolone

  brexanolone, chlorpromazine. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brexpiprazole

  chlorpromazine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP2D6 inhibitors. If also administered with a strong/moderate CYP3A4 inhibitor, administer a quarter of brexpiprazole dose. NOTE: In MDD clinical trials, brexpiprazole dosage was not adjusted for strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine); thus, CYP considerations are already factored into general dosing recommendations and brexpiprazole may be administered without dosage adjustment in patients with MDD.
  
  brexpiprazole and chlorpromazine both increase sedation. Use Caution/Monitor.

• brimonidine

  brimonidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• brivaracetam

  brivaracetam and chlorpromazine both increase sedation. Use Caution/Monitor.

• brompheniramine

  brompheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• buprenorphine

  buprenorphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• buprenorphine buccal

  buprenorphine buccal and chlorpromazine both increase sedation. Use Caution/Monitor.

• buprenorphine, long-acting injection

  chlorpromazine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• bupropion

  bupropion will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• butabarbital

  butabarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• butalbital

  butalbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• butorphanol

  butorphanol and chlorpromazine both increase sedation. Use Caution/Monitor.

• caffeine

  chlorpromazine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• capecitabine

  capecitabine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• carbinoxamine

  carbinoxamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• carisoprodol

  carisoprodol and chlorpromazine both increase sedation. Use Caution/Monitor.

• cenobamate

  cenobamate, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor.

• chloral hydrate

  chloral hydrate and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlordiazepoxide

  chlordiazepoxide and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlorpheniramine

  chlorpheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlorzoxazone

  chlorzoxazone and chlorpromazine both increase sedation. Use Caution/Monitor.

• cigarette smoking

  cigarette smoking decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• cinnarizine

  cinnarizine and chlorpromazine both increase sedation. Use Caution/Monitor.

• ciprofloxacin

  ciprofloxacin and chlorpromazine both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.

• cisatracurium

  cisatracurium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• citalopram

  chlorpromazine and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• clemastine

  clemastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• clobazam

  clobazam will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.
  
  chlorpromazine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

• clomipramine

  chlorpromazine and clomipramine both increase sedation. Use Caution/Monitor.

• clonazepam

  clonazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• clonidine

  clonidine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

  clorazepate and chlorpromazine both increase sedation. Use Caution/Monitor.

• clozapine

  chlorpromazine and clozapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and clozapine both increase sedation. Use Caution/Monitor.

• codeine

  codeine and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  chlorpromazine will decrease the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine

• crizotinib

  crizotinib and chlorpromazine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• cyclizine

  cyclizine and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  cyclizine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyclobenzaprine

  cyclobenzaprine and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyproheptadine

  cyproheptadine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dabrafenib

  dabrafenib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• dantrolene

  dantrolene and chlorpromazine both increase sedation. Use Caution/Monitor.

• daridorexant

  chlorpromazine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  darifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• dasatinib

  chlorpromazine and dasatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• desflurane

  desflurane and chlorpromazine both increase sedation. Use Caution/Monitor.

• desipramine

  chlorpromazine and desipramine both increase sedation. Use Caution/Monitor.

• desvenlafaxine

  desvenlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• deutetrabenazine

  chlorpromazine and deutetrabenazine both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• dexchlorpheniramine

  dexchlorpheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  chlorpromazine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, dexfenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dexmedetomidine

  dexmedetomidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  chlorpromazine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dextroamphetamine

  chlorpromazine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, dextroamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dextromoramide

  dextromoramide and chlorpromazine both increase sedation. Use Caution/Monitor.

• diamorphine

  diamorphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• diazepam

  diazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• dicyclomine

  dicyclomine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

  chlorpromazine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, diethylpropion. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• difelikefalin

  difelikefalin and chlorpromazine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

  difenoxin hcl and chlorpromazine both increase sedation. Use Caution/Monitor.

• dimenhydrinate

  dimenhydrinate and chlorpromazine both increase sedation. Use Caution/Monitor.

• diphenhydramine

  diphenhydramine and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  diphenhydramine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diphenoxylate hcl

  diphenoxylate hcl and chlorpromazine both increase sedation. Use Caution/Monitor.

• dipipanone

  dipipanone and chlorpromazine both increase sedation. Use Caution/Monitor.

• dobutamine

  chlorpromazine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, dobutamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dolasetron

  chlorpromazine and dolasetron both increase QTc interval. Modify Therapy/Monitor Closely.

• donepezil transdermal

  donepezil transdermal, chlorpromazine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dopamine

  chlorpromazine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, dopamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dopexamine

  chlorpromazine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dosulepin

  chlorpromazine and dosulepin both increase sedation. Use Caution/Monitor.

• doxepin

  chlorpromazine and doxepin both increase sedation. Use Caution/Monitor.

• doxylamine

  doxylamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• droperidol

  chlorpromazine and droperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and droperidol both increase sedation. Use Caution/Monitor.

• eliglustat

  eliglustat increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.

• eluxadoline

  chlorpromazine increases levels of eluxadoline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP2D6 inhibitors.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• ephedrine

  chlorpromazine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, ephedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• epinephrine

  chlorpromazine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, epinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.

• epinephrine racemic

  chlorpromazine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.

• esketamine intranasal

  esketamine intranasal, chlorpromazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• estazolam

  estazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• ethanol

  chlorpromazine and ethanol both increase sedation. Use Caution/Monitor.

• etomidate

  etomidate and chlorpromazine both increase sedation. Use Caution/Monitor.

• ezogabine

  ezogabine, chlorpromazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

• fedratinib

  fedratinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• fenfluramine

  chlorpromazine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, fenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• fesoterodine

  fesoterodine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flavoxate

  flavoxate decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flecainide

  chlorpromazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.

• floxuridine

  floxuridine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• fluoxetine

  chlorpromazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.

• fluphenazine

  chlorpromazine and fluphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and fluphenazine both increase sedation. Use Caution/Monitor.

• flurazepam

  flurazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• fluvoxamine

  fluvoxamine and chlorpromazine both increase QTc interval. Modify Therapy/Monitor Closely.

• formoterol

  chlorpromazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• foscarnet

  chlorpromazine and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.

• fostemsavir

  chlorpromazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• ganaxolone

  chlorpromazine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemtuzumab

  chlorpromazine and gemtuzumab both increase QTc interval. Use Caution/Monitor.

• glycopyrrolate

  chlorpromazine increases toxicity of glycopyrrolate by unknown mechanism. Use Caution/Monitor.
  
  chlorpromazine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrrolate inhaled

  glycopyrrolate inhaled decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  chlorpromazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.

• glycopyrronium tosylate topical

  glycopyrronium tosylate topical, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• goserelin

  goserelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• guanfacine

  guanfacine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  chlorpromazine and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and haloperidol both increase sedation. Use Caution/Monitor.

• henbane

  henbane decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• histrelin

  histrelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• homatropine

  homatropine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydromorphone

  hydromorphone and chlorpromazine both increase sedation. Use Caution/Monitor.

• hydroxyzine

  hydroxyzine and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  hydroxyzine increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• hyoscyamine

  hyoscyamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  chlorpromazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.

• iloperidone

  chlorpromazine and iloperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and iloperidone both increase sedation. Use Caution/Monitor.

• imipramine

  chlorpromazine and imipramine both increase sedation. Use Caution/Monitor.

• incobotulinumtoxinA

  chlorpromazine, incobotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• indacaterol, inhaled

  indacaterol, inhaled, chlorpromazine. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

• insulin degludec

  chlorpromazine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin degludec/insulin aspart

  chlorpromazine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin inhaled

  chlorpromazine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• ipratropium

  ipratropium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isoproterenol

  chlorpromazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, isoproterenol. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• itraconazole

  chlorpromazine and itraconazole both increase QTc interval. Use Caution/Monitor.

• ketamine

  ketamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• ketotifen, ophthalmic

  chlorpromazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• lapatinib

  chlorpromazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• lasmiditan

  lasmiditan, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• lemborexant

  lemborexant, chlorpromazine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• lenvatinib

  chlorpromazine and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

• leuprolide

  leuprolide increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• levalbuterol

  chlorpromazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levofloxacin

  chlorpromazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• levorphanol

  levorphanol and chlorpromazine both increase sedation. Use Caution/Monitor.

• liraglutide

  chlorpromazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• lisdexamfetamine

  chlorpromazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, lisdexamfetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• lithium

  lithium, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved.

• lofepramine

  chlorpromazine and lofepramine both increase sedation. Use Caution/Monitor.

• lofexidine

  chlorpromazine and lofexidine both increase sedation. Use Caution/Monitor.

• loprazolam

  loprazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• lorazepam

  lorazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• lorcaserin

  lorcaserin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lormetazepam

  lormetazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• loxapine

  chlorpromazine and loxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and loxapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  chlorpromazine and loxapine inhaled both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and loxapine inhaled both increase sedation. Use Caution/Monitor.

• lumefantrine

  lumefantrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lurasidone

  lurasidone, chlorpromazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• maprotiline

  chlorpromazine and maprotiline both increase sedation. Use Caution/Monitor.

• marijuana

  chlorpromazine and marijuana both increase sedation. Use Caution/Monitor.

• meclizine

  meclizine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• melatonin

  chlorpromazine and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  meperidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• meprobamate

  chlorpromazine and meprobamate both increase sedation. Use Caution/Monitor.

• metaproterenol

  chlorpromazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  metaxalone and chlorpromazine both increase sedation. Use Caution/Monitor.

• metformin

  chlorpromazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.

• methadone

  chlorpromazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  methadone and chlorpromazine both increase sedation. Use Caution/Monitor.

• methamphetamine

  chlorpromazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, methamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• methocarbamol

  methocarbamol and chlorpromazine both increase sedation. Use Caution/Monitor.

• methoxsalen

  methoxsalen, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

  methscopolamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methylenedioxymethamphetamine

  chlorpromazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, methylenedioxymethamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• methylphenidate

  chlorpromazine, methylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• metoclopramide

  chlorpromazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• midazolam

  midazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  midazolam intranasal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  chlorpromazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, midodrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• mifepristone

  mifepristone, chlorpromazine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• mipomersen

  mipomersen, chlorpromazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mirabegron

  mirabegron will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mirtazapine

  chlorpromazine and mirtazapine both increase sedation. Use Caution/Monitor.

• modafinil

  chlorpromazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• morphine

  morphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• motherwort

  chlorpromazine and motherwort both increase sedation. Use Caution/Monitor.

• moxonidine

  chlorpromazine and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  chlorpromazine and nabilone both increase sedation. Use Caution/Monitor.

• nalbuphine

  nalbuphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• norepinephrine

  chlorpromazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, norepinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• nortriptyline

  chlorpromazine and nortriptyline both increase sedation. Use Caution/Monitor.

• ofloxacin

  chlorpromazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• olanzapine

  chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.

• oliceridine

  oliceridine, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• olodaterol inhaled

  chlorpromazine and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• onabotulinumtoxinA

  onabotulinumtoxinA decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• opium tincture

  opium tincture and chlorpromazine both increase sedation. Use Caution/Monitor.

• orphenadrine

  orphenadrine and chlorpromazine both increase sedation. Use Caution/Monitor.

• osilodrostat

  osilodrostat and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• osimertinib

  osimertinib and chlorpromazine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

• oxaliplatin

  oxaliplatin will increase the level or effect of chlorpromazine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

• oxazepam

  oxazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• oxybutynin

  oxybutynin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin topical

  oxybutynin topical decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin transdermal

  oxybutynin transdermal decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxycodone

  oxycodone and chlorpromazine both increase sedation. Use Caution/Monitor.

• oxymorphone

  oxymorphone and chlorpromazine both increase sedation. Use Caution/Monitor.

• ozanimod

  ozanimod and chlorpromazine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paliperidone

  chlorpromazine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and paliperidone both increase sedation. Use Caution/Monitor.

• pancuronium

  pancuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• papaveretum

  papaveretum and chlorpromazine both increase sedation. Use Caution/Monitor.

• papaverine

  chlorpromazine and papaverine both increase sedation. Use Caution/Monitor.

• paroxetine

  chlorpromazine and paroxetine both increase QTc interval. Modify Therapy/Monitor Closely.

• pasireotide

  chlorpromazine and pasireotide both decrease QTc interval. Modify Therapy/Monitor Closely.

• pazopanib

  chlorpromazine and pazopanib both increase QTc interval. Use Caution/Monitor.

• peginterferon alfa 2b

  peginterferon alfa 2b, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• pentazocine

  pentazocine and chlorpromazine both increase sedation. Use Caution/Monitor.

• pentobarbital

  pentobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• perphenazine

  chlorpromazine and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and perphenazine both increase sedation. Use Caution/Monitor.

• phendimetrazine

  chlorpromazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, phendimetrazine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenobarbital

  phenobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• phentermine

  chlorpromazine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, phentermine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenylephrine

  chlorpromazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenylephrine PO

  chlorpromazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
  
  chlorpromazine, phenylephrine PO. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• pholcodine

  chlorpromazine and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  chlorpromazine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and pimozide both increase sedation. Use Caution/Monitor.

• pirbuterol

  chlorpromazine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• porfimer

  chlorpromazine, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.

• posaconazole

  chlorpromazine and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• pralidoxime

  pralidoxime decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• primidone

  primidone and chlorpromazine both increase sedation. Use Caution/Monitor.

• procarbazine

  procarbazine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.

• prochlorperazine

  chlorpromazine and prochlorperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and prochlorperazine both increase sedation. Use Caution/Monitor.

• promethazine

  chlorpromazine and promethazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and chlorpromazine both increase sedation. Use Caution/Monitor.

• propantheline

  propantheline decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

  propofol and chlorpromazine both increase sedation. Use Caution/Monitor.

• propylhexedrine

  chlorpromazine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, propylhexedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• protriptyline

  chlorpromazine and protriptyline both increase sedation. Use Caution/Monitor.

• pseudoephedrine

  chlorpromazine, pseudoephedrine. Mechanism: unknown. Use Caution/Monitor. Consider avoiding use of pseudoephedrine in patients receiving phenothiazines (especially thioridazine) due to the potential risk of cardiac arrhythmia or sudden death. Monitor for evidence of ventricular arrhythmias during concomitant use.

• quazepam

  quazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• quetiapine

  chlorpromazine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and quetiapine both increase sedation. Use Caution/Monitor.
  
  quetiapine, chlorpromazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.

• quinidine

  quinidine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• quinine

  chlorpromazine and quinine both increase QTc interval. Use Caution/Monitor.

• ramelteon

  chlorpromazine and ramelteon both increase sedation. Use Caution/Monitor.

• ranolazine

  chlorpromazine and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.

• rapacuronium

  rapacuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• rilpivirine

  rilpivirine increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsades de Pointes.

• rimabotulinumtoxinB

  chlorpromazine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  chlorpromazine and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and risperidone both increase sedation. Use Caution/Monitor.

• rocuronium

  rocuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• rolapitant

  rolapitant will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• romidepsin

  chlorpromazine and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.

• salmeterol

  chlorpromazine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• saquinavir

  saquinavir, chlorpromazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• scopolamine

  scopolamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

  chlorpromazine and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  secobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.

• selpercatinib

  selpercatinib increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor.

• serdexmethylphenidate/dexmethylphenidate

  chlorpromazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• sevoflurane

  sevoflurane and chlorpromazine both increase sedation. Use Caution/Monitor.

• shepherd's purse

  chlorpromazine and shepherd's purse both increase sedation. Use Caution/Monitor.

• smoking

  smoking decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• sodium picosulfate/magnesium oxide/anhydrous citric acid

  sodium picosulfate/magnesium oxide/anhydrous citric acid decreases levels of chlorpromazine by cation binding in GI tract. Use Caution/Monitor. Take at least 2 hours before and not less than 6 hours after administration of sodium picosulfate, magnesium oxide and anhydrous citric acid to avoid magnesium chelation .

• sodium sulfate/?magnesium sulfate/potassium chloride

  sodium sulfate/?magnesium sulfate/potassium chloride decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer chlorpromazine at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .
  
  sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

• sodium sulfate/potassium sulfate/magnesium sulfate

  sodium sulfate/potassium sulfate/magnesium sulfate decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer chlorpromazine at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .
  
  sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

• solifenacin

  solifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• sorafenib

  sorafenib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• stiripentol

  stiripentol, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• sufentanil

  sufentanil and chlorpromazine both increase sedation. Use Caution/Monitor.

• sulfamethoxazole

  chlorpromazine and sulfamethoxazole both increase QTc interval. Modify Therapy/Monitor Closely.

• tamoxifen

  chlorpromazine, tamoxifen. affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. CYP2D6 inhibition decreases metabolism of tamoxifen to hydroxytamoxifen, and N-desmethyl tamoxifen to endoxifen (active metabolites with 100-fold greater affinity for estrogen receptor); decreased endoxifen levels may result in poor clinical outcome.

• tamsulosin

  chlorpromazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tapentadol

  tapentadol and chlorpromazine both increase sedation. Use Caution/Monitor.

• teduglutide

  teduglutide increases levels of chlorpromazine by Other (see comment). Use Caution/Monitor. Comment: Teduglutide may increase absorption of concomitant PO medications; caution with with drugs requiring titration or those with a narrow therapeutic index; dose adjustment may be necessary.

• telavancin

  chlorpromazine and telavancin both increase QTc interval. Modify Therapy/Monitor Closely.

• temazepam

  temazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• terbinafine

  terbinafine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

• terbutaline

  chlorpromazine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• tetrabenazine

  chlorpromazine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.

• thalidomide

  thalidomide increases effects of chlorpromazine by unspecified interaction mechanism. Use Caution/Monitor. Increased sedative effects.

• thioridazine

  chlorpromazine and thioridazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and thioridazine both increase sedation. Use Caution/Monitor.

• thiothixene

  chlorpromazine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and thiothixene both increase sedation. Use Caution/Monitor.

• tiotropium

  tiotropium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tobacco use

  tobacco use decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• tolterodine

  tolterodine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

  chlorpromazine and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  tramadol and chlorpromazine both increase sedation. Use Caution/Monitor.

• tranylcypromine

  tranylcypromine, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: Coadministration of MAOI and phenothiazines may lead to additive hypotensive effects.

• trazodone

  chlorpromazine and trazodone both increase sedation. Use Caution/Monitor.

• triazolam

  triazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• triclofos

  triclofos and chlorpromazine both increase sedation. Use Caution/Monitor.

• trifluoperazine

  chlorpromazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• trihexyphenidyl

  trihexyphenidyl decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimethoprim

  chlorpromazine and trimethoprim both increase QTc interval. Modify Therapy/Monitor Closely.

• trimipramine

  chlorpromazine and trimipramine both increase sedation. Use Caution/Monitor.

• triprolidine

  triprolidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• triptorelin

  triptorelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• tropisetron

  chlorpromazine and tropisetron both increase QTc interval. Modify Therapy/Monitor Closely.

• trospium chloride

  trospium chloride decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• valbenazine

  chlorpromazine will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Consider reducing valbenazine dose based on tolerability if coadministered with a strong CYP2D6 inhibitor.
  
  valbenazine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• vecuronium

  vecuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• venlafaxine

  venlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  chlorpromazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.

• voclosporin

  voclosporin, chlorpromazine. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• voriconazole

  chlorpromazine and voriconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• xylometazoline

  chlorpromazine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, xylometazoline. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• yohimbine

  chlorpromazine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  chlorpromazine, yohimbine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• ziconotide

  chlorpromazine and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  chlorpromazine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and ziprasidone both increase sedation. Use Caution/Monitor.

• zolpidem

  chlorpromazine will increase the level or effect of zolpidem by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Additive effect of decreased alertness and psychomotor performance

• zotepine

  chlorpromazine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and zotepine both increase sedation. Use Caution/Monitor.

Minor (67)

• alfalfa

  alfalfa increases toxicity of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased photosensitivity.

• amiodarone

  amiodarone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• amitriptyline

  amitriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amitriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• amobarbital

  amobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• amoxapine

  amoxapine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amoxapine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• asenapine

  asenapine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• atropine

  chlorpromazine increases toxicity of atropine by unknown mechanism. Minor/Significance Unknown.

• atropine IV/IM

  chlorpromazine increases toxicity of atropine IV/IM by unknown mechanism. Minor/Significance Unknown.

• benazepril

  chlorpromazine increases effects of benazepril by unspecified interaction mechanism. Minor/Significance Unknown. Increased risk of hypotension.

• brimonidine

  brimonidine increases effects of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• butabarbital

  butabarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• butalbital

  butalbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• captopril

  chlorpromazine increases effects of captopril by unspecified interaction mechanism. Minor/Significance Unknown.

• celecoxib

  celecoxib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• chasteberry

  chasteberry decreases effects of chlorpromazine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• chloroquine

  chloroquine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  chloroquine increases levels of chlorpromazine by decreasing metabolism. Minor/Significance Unknown.

• cimetidine

  cimetidine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• clomipramine

  clomipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  clomipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• darifenacin

  darifenacin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• desipramine

  desipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  desipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• diphenhydramine

  diphenhydramine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• doxepin

  doxepin, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  doxepin, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• dronedarone

  dronedarone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• duloxetine

  duloxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• enalapril

  chlorpromazine increases effects of enalapril by unspecified interaction mechanism. Minor/Significance Unknown.

• ethanol

  ethanol, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• eucalyptus

  chlorpromazine and eucalyptus both increase sedation. Minor/Significance Unknown.

• fosinopril

  chlorpromazine increases effects of fosinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• haloperidol

  haloperidol will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imatinib

  imatinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imidapril

  chlorpromazine increases effects of imidapril by unspecified interaction mechanism. Minor/Significance Unknown.

• imipramine

  imipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  imipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• lisinopril

  chlorpromazine increases effects of lisinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• lofepramine

  lofepramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  lofepramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maprotiline

  maprotiline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  maprotiline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maraviroc

  maraviroc will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• marijuana

  marijuana will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• metyrapone

  chlorpromazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.

• metyrosine

  metyrosine increases toxicity of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.

• moexipril

  chlorpromazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.

• nilotinib

  nilotinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• nortriptyline

  nortriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  nortriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• orphenadrine

  orphenadrine decreases levels of chlorpromazine by unknown mechanism. Minor/Significance Unknown. Excessive anticholinergic effects and/or hypoglycemia possible.

• oxybutynin

  oxybutynin increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin topical

  oxybutynin topical increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin transdermal

  oxybutynin transdermal increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• parecoxib

  parecoxib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pentobarbital

  pentobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• perindopril

  chlorpromazine increases effects of perindopril by unspecified interaction mechanism. Minor/Significance Unknown.

• perphenazine

  perphenazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• phenobarbital

  phenobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• primidone

  primidone decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• protriptyline

  protriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  protriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• pyrimethamine

  pyrimethamine increases levels of chlorpromazine by decreasing metabolism. Minor/Significance Unknown.

• quinacrine

  quinacrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• quinapril

  chlorpromazine increases effects of quinapril by unspecified interaction mechanism. Minor/Significance Unknown.

• ramipril

  chlorpromazine increases effects of ramipril by unspecified interaction mechanism. Minor/Significance Unknown.

• ranolazine

  ranolazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ritonavir

  ritonavir will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• sage

  chlorpromazine and sage both increase sedation. Minor/Significance Unknown.

• secobarbital

  secobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• sertraline

  sertraline will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• thioridazine

  thioridazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tipranavir

  tipranavir will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trandolapril

  chlorpromazine increases effects of trandolapril by unspecified interaction mechanism. Minor/Significance Unknown.

• trazodone

  trazodone, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  trazodone, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.

• trimipramine

  trimipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  trimipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• abiraterone

  Monitor Closely (1)abiraterone increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

• abobotulinumtoxinA

  Monitor Closely (1)abobotulinumtoxinA increases effects of chlorpromazine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• aclidinium

  Monitor Closely (2)aclidinium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• acrivastine

  Monitor Closely (1)acrivastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• adagrasib

  Serious - Use Alternative (1)adagrasib, chlorpromazine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Each drug prolongs the QTc interval, which may increased the risk of Torsade de pointes, other serious arryhthmias, and sudden death. If coadministration unavoidable, more frequent monitoring is recommended for such patients.

• albiglutide

  Monitor Closely (1)chlorpromazine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• albuterol

  Monitor Closely (2)chlorpromazine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  albuterol and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• alfalfa

  Minor (1)alfalfa increases toxicity of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased photosensitivity.

• alfentanil

  Monitor Closely (1)alfentanil and chlorpromazine both increase sedation. Use Caution/Monitor.

• alfuzosin

  Monitor Closely (1)chlorpromazine and alfuzosin both increase QTc interval. Use Caution/Monitor.Serious - Use Alternative (1)alfuzosin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• alprazolam

  Monitor Closely (1)alprazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• amifampridine

  Monitor Closely (1)chlorpromazine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• aminolevulinic acid oral

  Serious - Use Alternative (1)aminolevulinic acid oral, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid administering other phototoxic drugs with aminolevulinic acid oral for 24 hr during perioperative period.

• aminolevulinic acid topical

  Serious - Use Alternative (1)chlorpromazine increases toxicity of aminolevulinic acid topical by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of photosensitizing drugs may enhance the phototoxic reaction to photodynamic therapy with aminolevulinic acid.

• amiodarone

  Serious - Use Alternative (1)chlorpromazine and amiodarone both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)amiodarone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• amisulpride

  Contraindicated (1)amisulpride, chlorpromazine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndrome.Serious - Use Alternative (1)chlorpromazine and amisulpride both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

• amitriptyline

  Monitor Closely (1)chlorpromazine and amitriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and amitriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)amitriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amitriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• amobarbital

  Monitor Closely (1)amobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)amobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• amoxapine

  Monitor Closely (2)chlorpromazine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and amoxapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and amoxapine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)amoxapine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amoxapine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• anagrelide

  Serious - Use Alternative (1)anagrelide and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• anticholinergic/sedative combos

  Monitor Closely (3)anticholinergic/sedative combos decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

  Monitor Closely (1)chlorpromazine and apomorphine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (2)apomorphine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.
  
  chlorpromazine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• arformoterol

  Monitor Closely (2)arformoterol and chlorpromazine both increase QTc interval. Use Caution/Monitor.
  
  chlorpromazine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  Monitor Closely (2)aripiprazole and chlorpromazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)aripiprazole and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• armodafinil

  Monitor Closely (1)chlorpromazine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• arsenic trioxide

  Serious - Use Alternative (1)chlorpromazine and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether

  Serious - Use Alternative (1)artemether and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  Monitor Closely (1)artemether/lumefantrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and artemether/lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  Monitor Closely (1)asenapine and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)asenapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)asenapine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• asenapine transdermal

  Monitor Closely (1)asenapine transdermal and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)asenapine transdermal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• atomoxetine

  Serious - Use Alternative (1)atomoxetine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• atracurium

  Monitor Closely (3)atracurium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  Monitor Closely (3)atropine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)chlorpromazine increases toxicity of atropine by unknown mechanism. Minor/Significance Unknown.

• atropine IV/IM

  Monitor Closely (3)chlorpromazine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.Minor (1)chlorpromazine increases toxicity of atropine IV/IM by unknown mechanism. Minor/Significance Unknown.

• avapritinib

  Monitor Closely (1)avapritinib and chlorpromazine both increase sedation. Use Caution/Monitor.

• azelastine

  Monitor Closely (1)azelastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• azithromycin

  Monitor Closely (1)chlorpromazine and azithromycin both increase QTc interval. Use Caution/Monitor.

• baclofen

  Monitor Closely (1)baclofen and chlorpromazine both increase sedation. Use Caution/Monitor.

• bedaquiline

  Monitor Closely (1)chlorpromazine and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

• belladonna alkaloids

  Monitor Closely (3)belladonna alkaloids decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  Monitor Closely (4)belladonna and opium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  belladonna and opium and chlorpromazine both increase sedation. Use Caution/Monitor.

• benazepril

  Minor (1)chlorpromazine increases effects of benazepril by unspecified interaction mechanism. Minor/Significance Unknown. Increased risk of hypotension.

• benperidol

  Monitor Closely (2)benperidol and chlorpromazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and chlorpromazine both increase sedation. Use Caution/Monitor.

• benzhydrocodone/acetaminophen

  Serious - Use Alternative (2)benzhydrocodone/acetaminophen, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).
  
  benzhydrocodone/acetaminophen and chlorpromazine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

• benzphetamine

  Monitor Closely (2)chlorpromazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• benztropine

  Monitor Closely (1)chlorpromazine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• bosutinib

  Monitor Closely (1)bosutinib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• brexanolone

  Monitor Closely (1)brexanolone, chlorpromazine. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brexpiprazole

  Monitor Closely (2)brexpiprazole and chlorpromazine both increase sedation. Use Caution/Monitor.
  
  chlorpromazine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer half of the usual brexpiprazole dose when coadministered with strong CYP2D6 inhibitors. If also administered with a strong/moderate CYP3A4 inhibitor, administer a quarter of brexpiprazole dose. NOTE: In MDD clinical trials, brexpiprazole dosage was not adjusted for strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine); thus, CYP considerations are already factored into general dosing recommendations and brexpiprazole may be administered without dosage adjustment in patients with MDD.

• brimonidine

  Monitor Closely (1)brimonidine and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)brimonidine increases effects of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• brivaracetam

  Monitor Closely (1)brivaracetam and chlorpromazine both increase sedation. Use Caution/Monitor.

• bromocriptine

  Serious - Use Alternative (1)chlorpromazine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• brompheniramine

  Monitor Closely (1)brompheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• buprenorphine

  Monitor Closely (1)buprenorphine and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)buprenorphine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine buccal

  Monitor Closely (1)buprenorphine buccal and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)buprenorphine buccal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine subdermal implant

  Serious - Use Alternative (2)buprenorphine subdermal implant and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.
  
  buprenorphine subdermal implant and chlorpromazine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate

• buprenorphine transdermal

  Serious - Use Alternative (1)buprenorphine transdermal and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• buprenorphine, long-acting injection

  Monitor Closely (1)chlorpromazine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.Serious - Use Alternative (1)buprenorphine, long-acting injection and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• bupropion

  Monitor Closely (1)bupropion will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine increases toxicity of bupropion by unspecified interaction mechanism. Avoid or Use Alternate Drug. May lower seizure threshold; keep bupropion dose as low as possible.

• butabarbital

  Monitor Closely (1)butabarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)butabarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• butalbital

  Monitor Closely (1)butalbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)butalbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• butorphanol

  Monitor Closely (1)butorphanol and chlorpromazine both increase sedation. Use Caution/Monitor.

• cabergoline

  Serious - Use Alternative (1)chlorpromazine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• caffeine

  Monitor Closely (1)chlorpromazine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• calcium/magnesium/potassium/sodium oxybates

  Serious - Use Alternative (1)chlorpromazine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• capecitabine

  Monitor Closely (1)capecitabine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• captopril

  Minor (1)chlorpromazine increases effects of captopril by unspecified interaction mechanism. Minor/Significance Unknown.

• carbinoxamine

  Monitor Closely (1)carbinoxamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• carisoprodol

  Monitor Closely (1)carisoprodol and chlorpromazine both increase sedation. Use Caution/Monitor.

• carvedilol

  Serious - Use Alternative (1)carvedilol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• celecoxib

  Minor (1)celecoxib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• cenobamate

  Monitor Closely (1)cenobamate, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor.

• ceritinib

  Serious - Use Alternative (1)ceritinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• chasteberry

  Minor (1)chasteberry decreases effects of chlorpromazine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• chloral hydrate

  Monitor Closely (1)chloral hydrate and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlordiazepoxide

  Monitor Closely (1)chlordiazepoxide and chlorpromazine both increase sedation. Use Caution/Monitor.

• chloroquine

  Serious - Use Alternative (1)chloroquine increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.Minor (2)chloroquine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  chloroquine increases levels of chlorpromazine by decreasing metabolism. Minor/Significance Unknown.

• chlorpheniramine

  Monitor Closely (1)chlorpheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• chlorzoxazone

  Monitor Closely (1)chlorzoxazone and chlorpromazine both increase sedation. Use Caution/Monitor.

• cigarette smoking

  Monitor Closely (1)cigarette smoking decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• cimetidine

  Minor (1)cimetidine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• cinnarizine

  Monitor Closely (1)cinnarizine and chlorpromazine both increase sedation. Use Caution/Monitor.

• ciprofloxacin

  Monitor Closely (1)ciprofloxacin and chlorpromazine both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.

• cisatracurium

  Monitor Closely (3)cisatracurium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• citalopram

  Monitor Closely (1)chlorpromazine and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• clarithromycin

  Serious - Use Alternative (1)chlorpromazine and clarithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• clemastine

  Monitor Closely (1)clemastine and chlorpromazine both increase sedation. Use Caution/Monitor.

• clobazam

  Monitor Closely (2)clobazam will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.
  
  chlorpromazine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

• clomipramine

  Monitor Closely (1)chlorpromazine and clomipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and clomipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)clomipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  clomipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• clonazepam

  Monitor Closely (1)clonazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• clonidine

  Monitor Closely (1)clonidine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

  Monitor Closely (1)clorazepate and chlorpromazine both increase sedation. Use Caution/Monitor.

• clozapine

  Monitor Closely (2)chlorpromazine and clozapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and clozapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)clozapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• codeine

  Monitor Closely (2)chlorpromazine will decrease the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine
  
  codeine and chlorpromazine both increase sedation. Use Caution/Monitor.

• crizotinib

  Monitor Closely (1)crizotinib and chlorpromazine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

• cyclizine

  Monitor Closely (4)cyclizine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclizine and chlorpromazine both increase sedation. Use Caution/Monitor.

• cyclobenzaprine

  Monitor Closely (3)cyclobenzaprine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclobenzaprine and chlorpromazine both increase sedation. Use Caution/Monitor.

• cyproheptadine

  Monitor Closely (1)cyproheptadine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dabrafenib

  Monitor Closely (1)dabrafenib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• dacomitinib

  Serious - Use Alternative (1)dacomitinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

• dantrolene

  Monitor Closely (1)dantrolene and chlorpromazine both increase sedation. Use Caution/Monitor.

• daridorexant

  Monitor Closely (1)chlorpromazine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  Monitor Closely (3)darifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dasatinib

  Monitor Closely (1)chlorpromazine and dasatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• degarelix

  Serious - Use Alternative (1)degarelix and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• desflurane

  Monitor Closely (1)desflurane and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)desflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• desipramine

  Monitor Closely (1)chlorpromazine and desipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and desipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)desipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  desipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• desvenlafaxine

  Monitor Closely (1)desvenlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• deutetrabenazine

  Monitor Closely (1)chlorpromazine and deutetrabenazine both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

• dexchlorpheniramine

  Monitor Closely (1)dexchlorpheniramine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  Monitor Closely (2)chlorpromazine, dexfenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dexmedetomidine

  Monitor Closely (1)dexmedetomidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  Monitor Closely (2)chlorpromazine, dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextroamphetamine

  Monitor Closely (2)chlorpromazine, dextroamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextromoramide

  Monitor Closely (1)dextromoramide and chlorpromazine both increase sedation. Use Caution/Monitor.

• diamorphine

  Monitor Closely (1)diamorphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• diazepam

  Monitor Closely (1)diazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• dicyclomine

  Monitor Closely (3)dicyclomine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

  Monitor Closely (2)chlorpromazine, diethylpropion. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• difelikefalin

  Monitor Closely (1)difelikefalin and chlorpromazine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

  Monitor Closely (1)difenoxin hcl and chlorpromazine both increase sedation. Use Caution/Monitor.

• dimenhydrinate

  Monitor Closely (1)dimenhydrinate and chlorpromazine both increase sedation. Use Caution/Monitor.

• diphenhydramine

  Monitor Closely (4)diphenhydramine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  diphenhydramine and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• diphenoxylate hcl

  Monitor Closely (1)diphenoxylate hcl and chlorpromazine both increase sedation. Use Caution/Monitor.

• dipipanone

  Monitor Closely (1)dipipanone and chlorpromazine both increase sedation. Use Caution/Monitor.

• disopyramide

  Contraindicated (1)chlorpromazine and disopyramide both increase QTc interval. Contraindicated.

• dobutamine

  Monitor Closely (2)chlorpromazine, dobutamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dofetilide

  Serious - Use Alternative (2)chlorpromazine and dofetilide both increase QTc interval. Avoid or Use Alternate Drug.
  
  dofetilide increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• dolasetron

  Monitor Closely (1)chlorpromazine and dolasetron both increase QTc interval. Modify Therapy/Monitor Closely.

• donepezil

  Serious - Use Alternative (1)donepezil and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• donepezil transdermal

  Monitor Closely (1)donepezil transdermal, chlorpromazine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dopamine

  Monitor Closely (2)chlorpromazine, dopamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• dopexamine

  Monitor Closely (1)chlorpromazine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dosulepin

  Monitor Closely (1)chlorpromazine and dosulepin both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and dosulepin both increase QTc interval. Avoid or Use Alternate Drug.

• doxepin

  Monitor Closely (1)chlorpromazine and doxepin both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and doxepin both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)doxepin, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  doxepin, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• doxylamine

  Monitor Closely (1)doxylamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• dronedarone

  Serious - Use Alternative (1)chlorpromazine and dronedarone both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)dronedarone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• droperidol

  Monitor Closely (2)chlorpromazine and droperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and droperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• duloxetine

  Minor (1)duloxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• efavirenz

  Serious - Use Alternative (1)efavirenz and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• eliglustat

  Contraindicated (1)chlorpromazine increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.Monitor Closely (1)eliglustat increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.Serious - Use Alternative (1)eliglustat and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• eluxadoline

  Monitor Closely (1)chlorpromazine increases levels of eluxadoline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP2D6 inhibitors.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Monitor Closely (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• enalapril

  Minor (1)chlorpromazine increases effects of enalapril by unspecified interaction mechanism. Minor/Significance Unknown.

• encorafenib

  Serious - Use Alternative (1)encorafenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• entrectinib

  Serious - Use Alternative (1)chlorpromazine and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.

• ephedrine

  Monitor Closely (2)chlorpromazine, ephedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine

  Monitor Closely (3)chlorpromazine, epinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.
  
  chlorpromazine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)epinephrine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine racemic

  Monitor Closely (2)chlorpromazine decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.
  
  chlorpromazine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)epinephrine racemic and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• eribulin

  Serious - Use Alternative (1)eribulin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

• erythromycin base

  Serious - Use Alternative (1)chlorpromazine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Serious - Use Alternative (1)chlorpromazine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Serious - Use Alternative (1)chlorpromazine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  Serious - Use Alternative (1)chlorpromazine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• escitalopram

  Serious - Use Alternative (1)escitalopram increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• esketamine intranasal

  Monitor Closely (1)esketamine intranasal, chlorpromazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• estazolam

  Monitor Closely (1)estazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• ethanol

  Monitor Closely (1)chlorpromazine and ethanol both increase sedation. Use Caution/Monitor.Minor (1)ethanol, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• etomidate

  Monitor Closely (1)etomidate and chlorpromazine both increase sedation. Use Caution/Monitor.

• eucalyptus

  Minor (1)chlorpromazine and eucalyptus both increase sedation. Minor/Significance Unknown.

• ezogabine

  Monitor Closely (1)ezogabine, chlorpromazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

• fenfluramine

  Monitor Closely (2)chlorpromazine, fenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fentanyl

  Serious - Use Alternative (1)fentanyl, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  Serious - Use Alternative (1)fentanyl intranasal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  Serious - Use Alternative (1)fentanyl transdermal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  Serious - Use Alternative (1)fentanyl transmucosal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fesoterodine

  Monitor Closely (3)fesoterodine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fexinidazole

  Serious - Use Alternative (1)fexinidazole and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels and/or prolong QT interval.

• fingolimod

  Serious - Use Alternative (1)fingolimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• flavoxate

  Monitor Closely (3)flavoxate decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flecainide

  Monitor Closely (1)chlorpromazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.

• floxuridine

  Monitor Closely (1)floxuridine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• fluconazole

  Serious - Use Alternative (1)chlorpromazine and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fluoxetine

  Monitor Closely (1)chlorpromazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)fluoxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• fluphenazine

  Monitor Closely (2)chlorpromazine and fluphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and fluphenazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and fluphenazine both increase QTc interval. Avoid or Use Alternate Drug.

• flurazepam

  Monitor Closely (1)flurazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• fluvoxamine

  Monitor Closely (1)fluvoxamine and chlorpromazine both increase QTc interval. Modify Therapy/Monitor Closely.

• formoterol

  Monitor Closely (1)chlorpromazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and formoterol both increase QTc interval. Avoid or Use Alternate Drug.

• foscarnet

  Monitor Closely (1)chlorpromazine and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.

• fosinopril

  Minor (1)chlorpromazine increases effects of fosinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• fostemsavir

  Monitor Closely (1)chlorpromazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

• gadobenate

  Serious - Use Alternative (1)gadobenate and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• ganaxolone

  Monitor Closely (1)chlorpromazine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemifloxacin

  Serious - Use Alternative (1)gemifloxacin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• gemtuzumab

  Monitor Closely (1)chlorpromazine and gemtuzumab both increase QTc interval. Use Caution/Monitor.

• gilteritinib

  Serious - Use Alternative (1)gilteritinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• givosiran

  Serious - Use Alternative (1)givosiran will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

• glasdegib

  Serious - Use Alternative (1)chlorpromazine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

• glycopyrrolate

  Monitor Closely (2)chlorpromazine increases toxicity of glycopyrrolate by unknown mechanism. Use Caution/Monitor.
  
  chlorpromazine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrrolate inhaled

  Monitor Closely (4)glycopyrrolate inhaled decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  chlorpromazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.

• glycopyrronium tosylate topical

  Monitor Closely (1)glycopyrronium tosylate topical, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• goserelin

  Monitor Closely (1)goserelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• granisetron

  Serious - Use Alternative (1)granisetron and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• guanfacine

  Monitor Closely (1)guanfacine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  Monitor Closely (2)chlorpromazine and haloperidol both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and haloperidol both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)haloperidol will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• henbane

  Monitor Closely (3)henbane decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• histrelin

  Monitor Closely (1)histrelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• homatropine

  Monitor Closely (3)homatropine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydrocodone

  Serious - Use Alternative (1)hydrocodone, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• hydromorphone

  Monitor Closely (1)hydromorphone and chlorpromazine both increase sedation. Use Caution/Monitor.

• hydroxychloroquine sulfate

  Serious - Use Alternative (1)hydroxychloroquine sulfate and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• hydroxyzine

  Monitor Closely (2)hydroxyzine increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.
  
  hydroxyzine and chlorpromazine both increase sedation. Use Caution/Monitor.

• hyoscyamine

  Monitor Closely (3)hyoscyamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  Monitor Closely (3)chlorpromazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.

• ibutilide

  Contraindicated (1)chlorpromazine and ibutilide both increase QTc interval. Contraindicated.

• iloperidone

  Monitor Closely (3)chlorpromazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and iloperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and iloperidone both increase sedation. Use Caution/Monitor.

• imatinib

  Minor (1)imatinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imidapril

  Minor (1)chlorpromazine increases effects of imidapril by unspecified interaction mechanism. Minor/Significance Unknown.

• imipramine

  Monitor Closely (1)chlorpromazine and imipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and imipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)imipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  imipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• incobotulinumtoxinA

  Monitor Closely (1)chlorpromazine, incobotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• indacaterol, inhaled

  Monitor Closely (1)indacaterol, inhaled, chlorpromazine. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

• indapamide

  Contraindicated (1)chlorpromazine and indapamide both increase QTc interval. Contraindicated.

• inotuzumab

  Serious - Use Alternative (1)inotuzumab and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

• insulin degludec

  Monitor Closely (1)chlorpromazine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin degludec/insulin aspart

  Monitor Closely (1)chlorpromazine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin inhaled

  Monitor Closely (1)chlorpromazine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• ipratropium

  Monitor Closely (3)ipratropium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isoflurane

  Serious - Use Alternative (1)isoflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• isoproterenol

  Monitor Closely (2)chlorpromazine, isoproterenol. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• itraconazole

  Monitor Closely (1)chlorpromazine and itraconazole both increase QTc interval. Use Caution/Monitor.

• ivosidenib

  Serious - Use Alternative (1)ivosidenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

• ketamine

  Monitor Closely (1)ketamine and chlorpromazine both increase sedation. Use Caution/Monitor.

• ketoconazole

  Serious - Use Alternative (1)chlorpromazine and ketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• ketotifen, ophthalmic

  Monitor Closely (1)chlorpromazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• lapatinib

  Monitor Closely (1)chlorpromazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• lasmiditan

  Monitor Closely (1)lasmiditan, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• lefamulin

  Serious - Use Alternative (1)lefamulin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• lemborexant

  Monitor Closely (1)lemborexant, chlorpromazine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• lenvatinib

  Monitor Closely (1)chlorpromazine and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

• leuprolide

  Monitor Closely (1)leuprolide increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• levalbuterol

  Monitor Closely (1)chlorpromazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levodopa

  Serious - Use Alternative (1)chlorpromazine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  Serious - Use Alternative (1)chlorpromazine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Phenothiazine/1st generation antipsychotics inhibit dopamine D2 receptors in varying degrees.

• levofloxacin

  Monitor Closely (1)chlorpromazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• levoketoconazole

  Serious - Use Alternative (1)chlorpromazine and levoketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• levorphanol

  Monitor Closely (1)levorphanol and chlorpromazine both increase sedation. Use Caution/Monitor.

• liraglutide

  Monitor Closely (1)chlorpromazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• lisdexamfetamine

  Monitor Closely (2)chlorpromazine, lisdexamfetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• lisinopril

  Minor (1)chlorpromazine increases effects of lisinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• lisuride

  Serious - Use Alternative (1)chlorpromazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lithium

  Monitor Closely (1)lithium, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved.Serious - Use Alternative (1)lithium and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• lofepramine

  Monitor Closely (1)chlorpromazine and lofepramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and lofepramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)lofepramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  lofepramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• lofexidine

  Monitor Closely (1)chlorpromazine and lofexidine both increase sedation. Use Caution/Monitor.

• loprazolam

  Monitor Closely (1)loprazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• lorazepam

  Monitor Closely (1)lorazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• lorcaserin

  Monitor Closely (1)lorcaserin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lormetazepam

  Monitor Closely (1)lormetazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• loxapine

  Monitor Closely (2)chlorpromazine and loxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and loxapine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  Monitor Closely (2)chlorpromazine and loxapine inhaled both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and loxapine inhaled both increase sedation. Use Caution/Monitor.

• lumefantrine

  Monitor Closely (1)lumefantrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• lurasidone

  Monitor Closely (1)lurasidone, chlorpromazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• macimorelin

  Serious - Use Alternative (1)macimorelin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

• maprotiline

  Monitor Closely (1)chlorpromazine and maprotiline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)maprotiline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  maprotiline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maraviroc

  Minor (1)maraviroc will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• marijuana

  Monitor Closely (1)chlorpromazine and marijuana both increase sedation. Use Caution/Monitor.Minor (1)marijuana will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• meclizine

  Monitor Closely (3)meclizine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• melatonin

  Monitor Closely (1)chlorpromazine and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  Monitor Closely (1)meperidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• meprobamate

  Monitor Closely (1)chlorpromazine and meprobamate both increase sedation. Use Caution/Monitor.

• metaproterenol

  Monitor Closely (1)chlorpromazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  Monitor Closely (1)metaxalone and chlorpromazine both increase sedation. Use Caution/Monitor.

• metformin

  Monitor Closely (1)chlorpromazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.

• methadone

  Monitor Closely (2)chlorpromazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  methadone and chlorpromazine both increase sedation. Use Caution/Monitor.

• methamphetamine

  Monitor Closely (2)chlorpromazine, methamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methocarbamol

  Monitor Closely (1)methocarbamol and chlorpromazine both increase sedation. Use Caution/Monitor.

• methoxsalen

  Monitor Closely (1)methoxsalen, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

  Monitor Closely (3)methscopolamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methyl aminolevulinate

  Serious - Use Alternative (1)chlorpromazine, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.

• methyldopa

  Serious - Use Alternative (1)chlorpromazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• methylenedioxymethamphetamine

  Monitor Closely (2)chlorpromazine, methylenedioxymethamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methylphenidate

  Monitor Closely (1)chlorpromazine, methylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• metoclopramide

  Monitor Closely (1)chlorpromazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• metoclopramide intranasal

  Serious - Use Alternative (2)chlorpromazine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  chlorpromazine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• metoprolol

  Serious - Use Alternative (1)metoprolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• metrizamide

  Contraindicated (1)chlorpromazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.

• metyrapone

  Minor (1)chlorpromazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.

• metyrosine

  Minor (1)metyrosine increases toxicity of chlorpromazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.

• midazolam

  Monitor Closely (1)midazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  Monitor Closely (1)midazolam intranasal, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  Monitor Closely (2)chlorpromazine, midodrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• mifepristone

  Monitor Closely (1)mifepristone, chlorpromazine. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

• mipomersen

  Monitor Closely (1)mipomersen, chlorpromazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

• mirabegron

  Monitor Closely (1)mirabegron will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• mirtazapine

  Monitor Closely (1)chlorpromazine and mirtazapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)mirtazapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• mobocertinib

  Serious - Use Alternative (1)mobocertinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

• modafinil

  Monitor Closely (1)chlorpromazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• moexipril

  Minor (1)chlorpromazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.

• morphine

  Monitor Closely (1)morphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• motherwort

  Monitor Closely (1)chlorpromazine and motherwort both increase sedation. Use Caution/Monitor.

• moxifloxacin

  Serious - Use Alternative (1)chlorpromazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• moxonidine

  Monitor Closely (1)chlorpromazine and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  Monitor Closely (1)chlorpromazine and nabilone both increase sedation. Use Caution/Monitor.

• nalbuphine

  Monitor Closely (1)nalbuphine and chlorpromazine both increase sedation. Use Caution/Monitor.

• nilotinib

  Serious - Use Alternative (1)chlorpromazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)nilotinib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• norepinephrine

  Monitor Closely (2)chlorpromazine, norepinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nortriptyline

  Monitor Closely (1)chlorpromazine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)nortriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  nortriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• octreotide

  Serious - Use Alternative (1)chlorpromazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide (Antidote)

  Serious - Use Alternative (1)chlorpromazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.

• ofloxacin

  Monitor Closely (1)chlorpromazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• olanzapine

  Monitor Closely (2)chlorpromazine and olanzapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and olanzapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)olanzapine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• oliceridine

  Monitor Closely (1)oliceridine, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• olodaterol inhaled

  Monitor Closely (1)chlorpromazine and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• olopatadine intranasal

  Serious - Use Alternative (1)chlorpromazine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• onabotulinumtoxinA

  Monitor Closely (3)onabotulinumtoxinA decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• ondansetron

  Serious - Use Alternative (1)chlorpromazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

• opium tincture

  Monitor Closely (1)opium tincture and chlorpromazine both increase sedation. Use Caution/Monitor.

• orphenadrine

  Monitor Closely (1)orphenadrine and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)orphenadrine decreases levels of chlorpromazine by unknown mechanism. Minor/Significance Unknown. Excessive anticholinergic effects and/or hypoglycemia possible.

• osilodrostat

  Monitor Closely (1)osilodrostat and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• osimertinib

  Monitor Closely (1)osimertinib and chlorpromazine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

• oxaliplatin

  Monitor Closely (1)oxaliplatin will increase the level or effect of chlorpromazine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.Serious - Use Alternative (1)oxaliplatin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• oxazepam

  Monitor Closely (1)oxazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• oxybutynin

  Monitor Closely (3)oxybutynin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin topical

  Monitor Closely (3)oxybutynin topical decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin topical increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin transdermal

  Monitor Closely (3)oxybutynin transdermal decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin transdermal increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxycodone

  Monitor Closely (1)oxycodone and chlorpromazine both increase sedation. Use Caution/Monitor.

• oxymorphone

  Monitor Closely (1)oxymorphone and chlorpromazine both increase sedation. Use Caution/Monitor.

• ozanimod

  Monitor Closely (1)ozanimod and chlorpromazine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

• paliperidone

  Monitor Closely (3)chlorpromazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and paliperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and paliperidone both increase sedation. Use Caution/Monitor.

• pancuronium

  Monitor Closely (3)pancuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• panobinostat

  Serious - Use Alternative (1)chlorpromazine and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

• papaveretum

  Monitor Closely (1)papaveretum and chlorpromazine both increase sedation. Use Caution/Monitor.

• papaverine

  Monitor Closely (1)chlorpromazine and papaverine both increase sedation. Use Caution/Monitor.

• parecoxib

  Minor (1)parecoxib will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• paroxetine

  Monitor Closely (1)chlorpromazine and paroxetine both increase QTc interval. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)paroxetine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• pasireotide

  Monitor Closely (1)chlorpromazine and pasireotide both decrease QTc interval. Modify Therapy/Monitor Closely.

• pazopanib

  Monitor Closely (1)chlorpromazine and pazopanib both increase QTc interval. Use Caution/Monitor.

• peginterferon alfa 2b

  Monitor Closely (1)peginterferon alfa 2b, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

• pentamidine

  Contraindicated (1)chlorpromazine and pentamidine both increase QTc interval. Contraindicated.

• pentazocine

  Monitor Closely (1)pentazocine and chlorpromazine both increase sedation. Use Caution/Monitor.

• pentobarbital

  Monitor Closely (1)pentobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)pentobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• perindopril

  Minor (1)chlorpromazine increases effects of perindopril by unspecified interaction mechanism. Minor/Significance Unknown.

• perphenazine

  Monitor Closely (2)chlorpromazine and perphenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and perphenazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and perphenazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)perphenazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pexidartinib

  Serious - Use Alternative (1)chlorpromazine and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.

• phendimetrazine

  Monitor Closely (2)chlorpromazine, phendimetrazine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenobarbital

  Monitor Closely (1)phenobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)phenobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• phentermine

  Monitor Closely (2)chlorpromazine, phentermine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine

  Monitor Closely (2)chlorpromazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine PO

  Monitor Closely (2)chlorpromazine, phenylephrine PO. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

• pholcodine

  Monitor Closely (1)chlorpromazine and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  Contraindicated (1)chlorpromazine and pimozide both increase QTc interval. Contraindicated.Monitor Closely (2)chlorpromazine and pimozide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and pimozide both increase sedation. Use Caution/Monitor.

• pirbuterol

  Monitor Closely (1)chlorpromazine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pitolisant

  Serious - Use Alternative (1)chlorpromazine and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

• ponesimod

  Serious - Use Alternative (1)ponesimod, chlorpromazine. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Consult cardiologist if considering treatment. Generally, should not be initiated in patients who are concurrently taking QT prolonging drugs with known arrhythmogenic properties, such as HR-lowering calcium channel blockers (eg, verapamil, diltiazem).

• porfimer

  Monitor Closely (1)chlorpromazine, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.

• posaconazole

  Monitor Closely (1)chlorpromazine and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• pralidoxime

  Monitor Closely (3)pralidoxime decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pramipexole

  Serious - Use Alternative (1)chlorpromazine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• primaquine

  Serious - Use Alternative (1)primaquine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• primidone

  Monitor Closely (1)primidone and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)primidone decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• procainamide

  Contraindicated (1)chlorpromazine and procainamide both increase QTc interval. Contraindicated.

• procarbazine

  Monitor Closely (1)procarbazine, chlorpromazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.

• prochlorperazine

  Monitor Closely (2)chlorpromazine and prochlorperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and prochlorperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and prochlorperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promazine

  Serious - Use Alternative (1)chlorpromazine and promazine both increase QTc interval. Avoid or Use Alternate Drug.

• promethazine

  Monitor Closely (2)chlorpromazine and promethazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and promethazine both increase QTc interval. Avoid or Use Alternate Drug.

• propafenone

  Serious - Use Alternative (1)propafenone will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

• propantheline

  Monitor Closely (3)propantheline decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

  Monitor Closely (1)propofol and chlorpromazine both increase sedation. Use Caution/Monitor.

• propranolol

  Serious - Use Alternative (1)propranolol, chlorpromazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

• propylhexedrine

  Monitor Closely (2)chlorpromazine, propylhexedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• protriptyline

  Monitor Closely (1)chlorpromazine and protriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and protriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)protriptyline, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  protriptyline, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• pseudoephedrine

  Monitor Closely (1)chlorpromazine, pseudoephedrine. Mechanism: unknown. Use Caution/Monitor. Consider avoiding use of pseudoephedrine in patients receiving phenothiazines (especially thioridazine) due to the potential risk of cardiac arrhythmia or sudden death. Monitor for evidence of ventricular arrhythmias during concomitant use.

• pyrimethamine

  Minor (1)pyrimethamine increases levels of chlorpromazine by decreasing metabolism. Minor/Significance Unknown.

• quazepam

  Monitor Closely (1)quazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• quetiapine

  Monitor Closely (3)chlorpromazine and quetiapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and quetiapine both increase sedation. Use Caution/Monitor.
  
  quetiapine, chlorpromazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.

• quinacrine

  Minor (1)quinacrine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• quinapril

  Minor (1)chlorpromazine increases effects of quinapril by unspecified interaction mechanism. Minor/Significance Unknown.

• quinidine

  Contraindicated (1)chlorpromazine and quinidine both increase QTc interval. Contraindicated.Monitor Closely (1)quinidine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)quinidine, chlorpromazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive cardiac effects.

• quinine

  Monitor Closely (1)chlorpromazine and quinine both increase QTc interval. Use Caution/Monitor.

• ramelteon

  Monitor Closely (1)chlorpromazine and ramelteon both increase sedation. Use Caution/Monitor.

• ramipril

  Minor (1)chlorpromazine increases effects of ramipril by unspecified interaction mechanism. Minor/Significance Unknown.

• ranolazine

  Monitor Closely (1)chlorpromazine and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.Minor (1)ranolazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• rapacuronium

  Monitor Closely (3)rapacuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• ribociclib

  Serious - Use Alternative (1)ribociclib increases toxicity of chlorpromazine by QTc interval. Avoid or Use Alternate Drug.

• rilpivirine

  Monitor Closely (1)rilpivirine increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsades de Pointes.

• rimabotulinumtoxinB

  Monitor Closely (1)chlorpromazine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  Monitor Closely (3)chlorpromazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  chlorpromazine and risperidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and risperidone both increase sedation. Use Caution/Monitor.

• ritonavir

  Minor (1)ritonavir will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• rocuronium

  Monitor Closely (3)rocuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• rolapitant

  Monitor Closely (1)rolapitant will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.

• romidepsin

  Monitor Closely (1)chlorpromazine and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.

• ropinirole

  Serious - Use Alternative (1)chlorpromazine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• sage

  Minor (1)chlorpromazine and sage both increase sedation. Minor/Significance Unknown.

• salmeterol

  Monitor Closely (1)chlorpromazine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• saquinavir

  Monitor Closely (1)saquinavir, chlorpromazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of PR or QT prolongation and cardiac arrhythmias.

• scopolamine

  Monitor Closely (3)scopolamine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

  Monitor Closely (1)chlorpromazine and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  Monitor Closely (1)secobarbital and chlorpromazine both increase sedation. Use Caution/Monitor.Minor (1)secobarbital decreases levels of chlorpromazine by increasing metabolism. Minor/Significance Unknown.

• selinexor

  Serious - Use Alternative (1)selinexor, chlorpromazine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• selpercatinib

  Monitor Closely (1)selpercatinib increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor.

• serdexmethylphenidate/dexmethylphenidate

  Monitor Closely (1)chlorpromazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• sertraline

  Serious - Use Alternative (1)sertraline and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)sertraline will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• sevoflurane

  Monitor Closely (1)sevoflurane and chlorpromazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)sevoflurane and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• shepherd's purse

  Monitor Closely (1)chlorpromazine and shepherd's purse both increase sedation. Use Caution/Monitor.

• siponimod

  Serious - Use Alternative (1)siponimod and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• smoking

  Monitor Closely (1)smoking decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• sodium oxybate

  Serious - Use Alternative (1)chlorpromazine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• sodium picosulfate/magnesium oxide/anhydrous citric acid

  Monitor Closely (1)sodium picosulfate/magnesium oxide/anhydrous citric acid decreases levels of chlorpromazine by cation binding in GI tract. Use Caution/Monitor. Take at least 2 hours before and not less than 6 hours after administration of sodium picosulfate, magnesium oxide and anhydrous citric acid to avoid magnesium chelation .

• sodium sulfate/?magnesium sulfate/potassium chloride

  Monitor Closely (2)sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .
  
  sodium sulfate/?magnesium sulfate/potassium chloride decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer chlorpromazine at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .

• sodium sulfate/potassium sulfate/magnesium sulfate

  Monitor Closely (2)sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .
  
  sodium sulfate/potassium sulfate/magnesium sulfate decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer chlorpromazine at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .

• solifenacin

  Monitor Closely (3)solifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Serious - Use Alternative (1)solifenacin and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• sorafenib

  Monitor Closely (1)sorafenib and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• sotalol

  Contraindicated (1)chlorpromazine and sotalol both increase QTc interval. Contraindicated.

• stiripentol

  Monitor Closely (1)stiripentol, chlorpromazine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

• sufentanil

  Monitor Closely (1)sufentanil and chlorpromazine both increase sedation. Use Caution/Monitor.

• sulfamethoxazole

  Monitor Closely (1)chlorpromazine and sulfamethoxazole both increase QTc interval. Modify Therapy/Monitor Closely.

• sunitinib

  Serious - Use Alternative (1)sunitinib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• tacrolimus

  Serious - Use Alternative (1)tacrolimus and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• tamoxifen

  Monitor Closely (1)chlorpromazine, tamoxifen. affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. CYP2D6 inhibition decreases metabolism of tamoxifen to hydroxytamoxifen, and N-desmethyl tamoxifen to endoxifen (active metabolites with 100-fold greater affinity for estrogen receptor); decreased endoxifen levels may result in poor clinical outcome.

• tamsulosin

  Monitor Closely (1)chlorpromazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tapentadol

  Monitor Closely (1)tapentadol and chlorpromazine both increase sedation. Use Caution/Monitor.

• teduglutide

  Monitor Closely (1)teduglutide increases levels of chlorpromazine by Other (see comment). Use Caution/Monitor. Comment: Teduglutide may increase absorption of concomitant PO medications; caution with with drugs requiring titration or those with a narrow therapeutic index; dose adjustment may be necessary.

• telavancin

  Monitor Closely (1)chlorpromazine and telavancin both increase QTc interval. Modify Therapy/Monitor Closely.

• temazepam

  Monitor Closely (1)temazepam and chlorpromazine both increase sedation. Use Caution/Monitor.

• terbinafine

  Monitor Closely (1)terbinafine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

• terbutaline

  Monitor Closely (1)chlorpromazine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• tetrabenazine

  Monitor Closely (1)chlorpromazine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.Serious - Use Alternative (1)tetrabenazine and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• thalidomide

  Monitor Closely (1)thalidomide increases effects of chlorpromazine by unspecified interaction mechanism. Use Caution/Monitor. Increased sedative effects.

• thioridazine

  Monitor Closely (2)chlorpromazine and thioridazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and thioridazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and thioridazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)thioridazine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• thiothixene

  Monitor Closely (2)chlorpromazine and thiothixene both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and thiothixene both increase sedation. Use Caution/Monitor.

• tiotropium

  Monitor Closely (3)tiotropium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tipranavir

  Minor (1)tipranavir will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tobacco use

  Monitor Closely (1)tobacco use decreases levels of chlorpromazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• tolterodine

  Monitor Closely (3)tolterodine decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

  Monitor Closely (1)chlorpromazine and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  Monitor Closely (1)tramadol and chlorpromazine both increase sedation. Use Caution/Monitor.

• trandolapril

  Minor (1)chlorpromazine increases effects of trandolapril by unspecified interaction mechanism. Minor/Significance Unknown.

• tranylcypromine

  Monitor Closely (1)tranylcypromine, chlorpromazine. Other (see comment). Use Caution/Monitor. Comment: Coadministration of MAOI and phenothiazines may lead to additive hypotensive effects.

• trazodone

  Monitor Closely (1)chlorpromazine and trazodone both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and trazodone both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)trazodone, chlorpromazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  trazodone, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.

• tretinoin

  Serious - Use Alternative (1)chlorpromazine, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• tretinoin topical

  Serious - Use Alternative (1)chlorpromazine, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• triazolam

  Monitor Closely (1)triazolam and chlorpromazine both increase sedation. Use Caution/Monitor.

• triclofos

  Monitor Closely (1)triclofos and chlorpromazine both increase sedation. Use Caution/Monitor.

• trifluoperazine

  Monitor Closely (2)chlorpromazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• trihexyphenidyl

  Monitor Closely (2)trihexyphenidyl decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimethoprim

  Monitor Closely (1)chlorpromazine and trimethoprim both increase QTc interval. Modify Therapy/Monitor Closely.

• trimipramine

  Monitor Closely (1)chlorpromazine and trimipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and trimipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)trimipramine, chlorpromazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  trimipramine, chlorpromazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• triprolidine

  Monitor Closely (1)triprolidine and chlorpromazine both increase sedation. Use Caution/Monitor.

• triptorelin

  Monitor Closely (1)triptorelin increases toxicity of chlorpromazine by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.

• tropisetron

  Monitor Closely (1)chlorpromazine and tropisetron both increase QTc interval. Modify Therapy/Monitor Closely.

• trospium chloride

  Monitor Closely (3)trospium chloride decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• umeclidinium bromide/vilanterol inhaled

  Serious - Use Alternative (1)chlorpromazine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• valbenazine

  Monitor Closely (2)chlorpromazine will increase the level or effect of valbenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Consider reducing valbenazine dose based on tolerability if coadministered with a strong CYP2D6 inhibitor.
  
  valbenazine and chlorpromazine both increase QTc interval. Use Caution/Monitor.

• vandetanib

  Serious - Use Alternative (1)chlorpromazine, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.

• vecuronium

  Monitor Closely (3)vecuronium decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• vemurafenib

  Serious - Use Alternative (1)vemurafenib and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended.

• venlafaxine

  Monitor Closely (2)chlorpromazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• vilanterol/fluticasone furoate inhaled

  Serious - Use Alternative (1)chlorpromazine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

• voclosporin

  Monitor Closely (1)voclosporin, chlorpromazine. Either increases effects of the other by QTc interval. Use Caution/Monitor.

• voriconazole

  Monitor Closely (1)chlorpromazine and voriconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• vorinostat

  Serious - Use Alternative (1)vorinostat and chlorpromazine both increase QTc interval. Avoid or Use Alternate Drug.

• vortioxetine

  Serious - Use Alternative (1)chlorpromazine increases levels of vortioxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Decrease vortioxetine dose by 50% when coadministered with strong CYP2D6 inhibitors.

• xylometazoline

  Monitor Closely (2)chlorpromazine, xylometazoline. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• yohimbe

  Serious - Use Alternative (1)yohimbe decreases effects of chlorpromazine by pharmacodynamic antagonism. Contraindicated.

• yohimbine

  Monitor Closely (2)chlorpromazine, yohimbine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  chlorpromazine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ziconotide

  Monitor Closely (1)chlorpromazine and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  Monitor Closely (2)chlorpromazine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and ziprasidone both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

• zolpidem

  Monitor Closely (1)chlorpromazine will increase the level or effect of zolpidem by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Additive effect of decreased alertness and psychomotor performance

• zotepine

  Monitor Closely (2)chlorpromazine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and zotepine both increase sedation. Use Caution/Monitor.