Dosing & Uses
Dosing Forms & Strengths
dihydrocodeine/chlorpheniramine/phenylephrine
oral liquid: Schedule III
- (7.5mg/2mg/5mg)/5mL
oral syrup: Schedule V
- (3mg/2mg/7.5mg)/5mL
- (3mg/5mg/20mg)/5mL
Cough and Congestion
5-10 mL PO q4-6hr, up to 40 mL/24 hr
Dosage Forms & Strengths
dihydrocodeine/chlorpheniramine/phenylephrine
oral liquid: Schedule III
- (7.25mg/2mg/5mg)/5mL
oral syrup: Schedule V
- (3mg/2mg/7.5mg)/5mL
- (3mg/5mg/20mg)/5mL
Cough and Congestion
< 2 years: Not recommended
2-6 years: 1.25-2.5 mL PO q4-6hr PRN, up to 10 mL/24 hr
6-12 years: 2.5-5 mL PO q4-6hr, up to 20 mL/24 hr
>12 years: 5-10 mL PO q4-6hr, up to 40 mL/24 hr
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (2)
- alvimopan
alvimopan, codeine. receptor binding competition. Contraindicated. Alvimopan is contraindicated in opioid tolerant patients (ie, those who have taken therapeutic doses of opioids for >7 consecutive days immediately prior to taking alvimopan). Patients recently exposed to opioids are expected to be more sensitive to the effects of alvimopan and therefore may experience abdominal pain, nausea and vomiting, and diarrhea. No significant interaction is expected with concurrent use of opioid analgesics and alvimopan in patients who received opioid analgesics for 7 or fewer consecutive days prior to alvimopan.
- iobenguane I 123
phenylephrine decreases effects of iobenguane I 123 by receptor binding competition. Contraindicated. If clinically appropriate, discontinue drugs that compete for NE receptor sites for at least 5 half-lives; may cause false-negative imaging results.
Serious - Use Alternative (81)
- abametapir
abametapir will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.
- acrivastine
acrivastine and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- amisulpride
amisulpride and codeine both increase sedation. Avoid or Use Alternate Drug.
- amitriptyline
amitriptyline, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- amoxapine
amoxapine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- apalutamide
apalutamide will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.
- asenapine
asenapine and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- asenapine transdermal
asenapine transdermal and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- avapritinib
avapritinib and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- benzhydrocodone/acetaminophen
benzhydrocodone/acetaminophen and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
benzhydrocodone/acetaminophen and chlorpheniramine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
benzhydrocodone/acetaminophen, codeine. 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. - bremelanotide
bremelanotide will decrease the level or effect of codeine by Other (see comment). Avoid or Use Alternate Drug. Bremelanotide may slow gastric emptying and potentially reduces the rate and extent of absorption of concomitantly administered oral medications. Avoid use when taking any oral drug that is dependent on threshold concentrations for efficacy. Interactions listed are representative examples and do not include all possible clinical examples.
- buprenorphine subdermal implant
buprenorphine subdermal implant and chlorpheniramine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- brimonidine
brimonidine and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- buprenorphine
buprenorphine, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.
- buprenorphine buccal
buprenorphine buccal, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.
- buprenorphine subdermal implant
buprenorphine subdermal implant and codeine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- butorphanol
butorphanol, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.
- cabergoline
cabergoline, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- calcium/magnesium/potassium/sodium oxybates
chlorpheniramine, 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.
codeine, 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. - clomipramine
clomipramine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- clonidine
clonidine, codeine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration enhances CNS depressant effects.
- desflurane
desflurane increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
desflurane increases levels of phenylephrine by decreasing metabolism. Contraindicated. - desipramine
desipramine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- dihydroergotamine
dihydroergotamine, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- dihydroergotamine intranasal
dihydroergotamine intranasal, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- doxapram
doxapram increases effects of phenylephrine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive pressor effect.
- doxepin
doxepin, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- eluxadoline
chlorpheniramine, eluxadoline. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that cause constipation. Increases risk for constipation related serious adverse reactions.
- dacomitinib
dacomitinib will increase the level or effect of codeine 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.
- diazepam intranasal
diazepam intranasal, codeine. 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.
- eluxadoline
codeine, eluxadoline. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that cause constipation. Increases risk for constipation related serious adverse reactions. .
- ergoloid mesylates
ergoloid mesylates, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- ergotamine
ergotamine, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- ether
ether increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- etomidate
etomidate increases levels of phenylephrine by decreasing metabolism. Contraindicated.
- fentanyl
fentanyl, codeine. 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, codeine. 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, codeine. 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, codeine. 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 will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.
- givosiran
givosiran will increase the level or effect of codeine 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.
- hydrocodone
hydrocodone, codeine. 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.
- idelalisib
idelalisib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
- imipramine
imipramine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- isocarboxazid
isocarboxazid increases effects of chlorpheniramine by Other (see comment). Avoid or Use Alternate Drug. Comment: Isocarboxazid should not be administered in combination with antihistamines because of potential additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
isocarboxazid increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d. - isoflurane
isoflurane increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- linezolid
linezolid increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.
- lofepramine
lofepramine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- lonafarnib
lonafarnib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.
- maprotiline
maprotiline, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- methoxyflurane
methoxyflurane increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- methylene blue
methylene blue and codeine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities
- methylergonovine
methylergonovine, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- metoclopramide intranasal
chlorpheniramine, 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.
codeine, 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. - nalbuphine
nalbuphine, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.
- nortriptyline
nortriptyline, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- olopatadine intranasal
chlorpheniramine 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.
- olopatadine intranasal
codeine 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.
- ozanimod
ozanimod and codeine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.
- pentazocine
pentazocine, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Mixed opiate agonist/antagonists usually produce additive sedation with narcotics; however, in narcotic addicted pts., the antagonist activity may provoke withdrawal Sx.
- phenelzine
phenelzine increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.
- prasugrel
codeine will decrease the level or effect of prasugrel by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Co-administration of opioid agonists delay and reduce absorption of prasugrel and its active metabolite presumably by slowing gastric emptying; consider the use of a parenteral anti-platelet agent in acute coronary syndrome patients requiring co-administration of opioid agonists
- procarbazine
procarbazine increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. MAOIs may potentiate CNS depression and hypotension. Do not use within 14 days of MAOI use. .
- propofol
propofol increases levels of phenylephrine by decreasing metabolism. Contraindicated.
- protriptyline
protriptyline, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- rasagiline
rasagiline increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death.
- selegiline transdermal
selegiline transdermal increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death.
- selinexor
selinexor, codeine. 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.
- sevoflurane
sevoflurane increases toxicity of phenylephrine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
sevoflurane increases levels of phenylephrine by decreasing metabolism. Contraindicated. - sodium oxybate
chlorpheniramine, 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.
codeine, 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. - sufentanil SL
sufentanil SL, codeine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. 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.
- tranylcypromine
tranylcypromine increases effects of chlorpheniramine by Other (see comment). Avoid or Use Alternate Drug. Comment: Tranylcypromine should not be administered in combination with antihistamines because of potential additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- ticagrelor
codeine will decrease the level or effect of ticagrelor by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Co-administration of opioid agonists delay and reduce absorption of ticagrelor and its active metabolite presumably by slowing gastric emptying; consider the use of a parenteral anti-platelet agent in acute coronary syndrome patients requiring co-administration of opioid agonists
- tramadol
tramadol, codeine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tramadol may reinitiate opiate dependence in pts. previously addicted to other opiates; it may also provoke withdrawal Sx. in pts. who are currently opiate dependent.
- tranylcypromine
tranylcypromine increases toxicity of codeine by unknown mechanism. Avoid or Use Alternate Drug. Risk of hypotension, hyperpyrexia, somnolence, or death; separate by 14 d.
- trazodone
trazodone, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- trimipramine
trimipramine, phenylephrine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- tucatinib
tucatinib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.
- valerian
valerian and codeine both increase sedation. Avoid or Use Alternate Drug.
- voxelotor
voxelotor will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.
- yohimbe
yohimbe, phenylephrine. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
Monitor Closely (359)
- abiraterone
abiraterone increases levels of codeine 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.
- acrivastine
acrivastine and chlorpheniramine both increase sedation. Use Caution/Monitor.
- albuterol
albuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
albuterol and phenylephrine both decrease sedation. Use Caution/Monitor. - alfentanil
alfentanil increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and alfentanil both increase sedation. Use Caution/Monitor.
alfentanil and codeine both increase sedation. Use Caution/Monitor. - alprazolam
alprazolam and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and alprazolam both increase sedation. Use Caution/Monitor.
alprazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - amifampridine
chlorpheniramine 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
amitriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- amiodarone
amiodarone will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- amisulpride
amisulpride and chlorpheniramine both increase sedation. Use Caution/Monitor.
- amitriptyline
chlorpheniramine and amitriptyline both increase sedation. Use Caution/Monitor.
codeine and amitriptyline both increase sedation. Use Caution/Monitor. - amobarbital
amobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
amobarbital will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
amobarbital and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and amobarbital both increase sedation. Use Caution/Monitor. - amoxapine
amoxapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and amoxapine both increase sedation. Use Caution/Monitor.
chlorpheniramine and amoxapine both increase sedation. Use Caution/Monitor. - apomorphine
codeine and apomorphine both increase sedation. Use Caution/Monitor.
chlorpheniramine and apomorphine both increase sedation. Use Caution/Monitor. - arformoterol
arformoterol and phenylephrine both decrease sedation. Use Caution/Monitor.
arformoterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - arformoterol
chlorpheniramine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - aripiprazole
aripiprazole increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and aripiprazole both increase sedation. Use Caution/Monitor.
chlorpheniramine and aripiprazole both increase sedation. Use Caution/Monitor. - armodafinil
codeine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
armodafinil and phenylephrine both decrease sedation. Use Caution/Monitor. - artemether/lumefantrine
artemether/lumefantrine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- atomoxetine
atomoxetine, phenylephrine. Other (see comment). Use Caution/Monitor. Comment: Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine.
- asenapine
asenapine and chlorpheniramine both increase sedation. Use Caution/Monitor.
- asenapine transdermal
asenapine transdermal and chlorpheniramine both increase sedation. Use Caution/Monitor.
- avapritinib
avapritinib and chlorpheniramine both increase sedation. Use Caution/Monitor.
- azelastine
azelastine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
azelastine and codeine both increase sedation. Use Caution/Monitor.
azelastine and chlorpheniramine both increase sedation. Use Caution/Monitor. - baclofen
chlorpheniramine and baclofen both increase sedation. Use Caution/Monitor.
baclofen and codeine both increase sedation. Use Caution/Monitor. - belladonna and opium
belladonna and opium increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- belladonna and opium
codeine and belladonna and opium both increase sedation. Use Caution/Monitor.
chlorpheniramine and belladonna and opium both increase sedation. Use Caution/Monitor. - belzutifan
belzutifan will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.
- benperidol
codeine and benperidol both increase sedation. Use Caution/Monitor.
benperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - benperidol
chlorpheniramine and benperidol both increase sedation. Use Caution/Monitor.
- benzphetamine
benzphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.
benzphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - benzphetamine
chlorpheniramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - brexanolone
brexanolone, codeine. Either increases toxicity of the other by sedation. Use Caution/Monitor.
brexanolone, chlorpheniramine. Either increases toxicity of the other by sedation. Use Caution/Monitor. - brexpiprazole
brexpiprazole and chlorpheniramine both increase sedation. Use Caution/Monitor.
brexpiprazole and codeine both increase sedation. Use Caution/Monitor. - brimonidine
brimonidine and chlorpheniramine both increase sedation. Use Caution/Monitor.
- brivaracetam
brivaracetam and codeine both increase sedation. Use Caution/Monitor.
- brivaracetam
brivaracetam and chlorpheniramine both increase sedation. Use Caution/Monitor.
- bromocriptine
bromocriptine, phenylephrine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Hypertension, V tach.
- brompheniramine
brompheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
brompheniramine and codeine both increase sedation. Use Caution/Monitor.
brompheniramine and chlorpheniramine both increase sedation. Use Caution/Monitor. - buprenorphine
buprenorphine and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and buprenorphine both increase sedation. Use Caution/Monitor. - buprenorphine buccal
buprenorphine buccal increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- buprenorphine buccal
chlorpheniramine and buprenorphine buccal both increase sedation. Use Caution/Monitor.
buprenorphine buccal and codeine both increase sedation. Use Caution/Monitor. - buprenorphine, long-acting injection
codeine 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.
- butabarbital
butabarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and butabarbital both increase sedation. Use Caution/Monitor. - bupropion
bupropion will decrease the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents the conversion of codeine to its active metabolite morphine.
- butalbital
butalbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- butabarbital
butabarbital and codeine both increase sedation. Use Caution/Monitor.
- butalbital
chlorpheniramine and butalbital both increase sedation. Use Caution/Monitor.
butalbital and codeine both increase sedation. Use Caution/Monitor. - butorphanol
butorphanol and codeine both increase sedation. Use Caution/Monitor.
butorphanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and butorphanol both increase sedation. Use Caution/Monitor. - caffeine
chlorpheniramine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
caffeine and phenylephrine both decrease sedation. Use Caution/Monitor. - carbinoxamine
carbinoxamine and chlorpheniramine both increase sedation. Use Caution/Monitor.
carbinoxamine and codeine both increase sedation. Use Caution/Monitor.
carbinoxamine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - carisoprodol
carisoprodol and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and carisoprodol both increase sedation. Use Caution/Monitor. - chloral hydrate
chloral hydrate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- celecoxib
celecoxib decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- cenobamate
cenobamate will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
cenobamate, chlorpheniramine. Either increases effects of the other by sedation. Use Caution/Monitor. - cenobamate
cenobamate, codeine. Either increases effects of the other by sedation. Use Caution/Monitor.
- chloral hydrate
chloral hydrate and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and chloral hydrate both increase sedation. Use Caution/Monitor. - chlordiazepoxide
chlorpheniramine and chlordiazepoxide both increase sedation. Use Caution/Monitor.
chlordiazepoxide and codeine both increase sedation. Use Caution/Monitor.
chlordiazepoxide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - chloroquine
chloroquine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- chlorpheniramine
chlorpheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorpromazine
chlorpheniramine and chlorpromazine both increase sedation. 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.
chlorpromazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - chlorpheniramine
chlorpheniramine and codeine both increase sedation. Use Caution/Monitor.
- cinnarizine
cinnarizine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorpromazine
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 - chlorzoxazone
chlorzoxazone and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and chlorzoxazone both increase sedation. Use Caution/Monitor. - cimetidine
cimetidine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- cinnarizine
chlorpheniramine and cinnarizine both increase sedation. Use Caution/Monitor.
- cinacalcet
cinacalcet decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- cinnarizine
cinnarizine and codeine both increase sedation. Use Caution/Monitor.
- clemastine
clemastine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and clemastine both increase sedation. Use Caution/Monitor.
clemastine and codeine both increase sedation. Use Caution/Monitor. - clobazam
chlorpheniramine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
codeine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
clobazam decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. - clomipramine
clomipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clomipramine
codeine and clomipramine both increase sedation. Use Caution/Monitor.
chlorpheniramine and clomipramine both increase sedation. Use Caution/Monitor.
clomipramine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. - clonazepam
clonazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and clonazepam both increase sedation. Use Caution/Monitor.
clonazepam and codeine both increase sedation. Use Caution/Monitor. - clorazepate
clorazepate and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and clorazepate both increase sedation. Use Caution/Monitor.
clorazepate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - clozapine
codeine and clozapine both increase sedation. Use Caution/Monitor.
clozapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and clozapine both increase sedation. Use Caution/Monitor.
clozapine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. - cocaine topical
cocaine topical decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- codeine
codeine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- codeine
chlorpheniramine and codeine both increase sedation. Use Caution/Monitor.
- crofelemer
crofelemer increases levels of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
- cyclizine
cyclizine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and cyclizine both increase sedation. Use Caution/Monitor.
cyclizine and codeine both increase sedation. Use Caution/Monitor. - cyclobenzaprine
chlorpheniramine and cyclobenzaprine both increase sedation. Use Caution/Monitor.
cyclobenzaprine and codeine both increase sedation. Use Caution/Monitor. - cyproheptadine
cyproheptadine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cyproheptadine
cyproheptadine and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and cyproheptadine both increase sedation. Use Caution/Monitor. - dabrafenib
dabrafenib will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
- dantrolene
dantrolene and codeine both increase sedation. Use Caution/Monitor.
- dantrolene
chlorpheniramine and dantrolene both increase sedation. Use Caution/Monitor.
- daridorexant
chlorpheniramine 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.
codeine 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 effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- desflurane
desflurane and chlorpheniramine both increase sedation. Use Caution/Monitor.
- desflurane
desflurane and codeine both increase sedation. Use Caution/Monitor. Opioids may decrease MAC requirements, less inhalation anesthetic may be required.
- desipramine
chlorpheniramine and desipramine both increase sedation. Use Caution/Monitor.
codeine and desipramine both increase sedation. Use Caution/Monitor.
desipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
desipramine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. - desvenlafaxine
desvenlafaxine will increase the level or effect of codeine 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
- dexchlorpheniramine
dexchlorpheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- deutetrabenazine
chlorpheniramine and deutetrabenazine both increase sedation. Use Caution/Monitor.
- deutetrabenazine
codeine and deutetrabenazine both increase sedation. Use Caution/Monitor.
- dexchlorpheniramine
chlorpheniramine and dexchlorpheniramine both increase sedation. Use Caution/Monitor.
dexchlorpheniramine and codeine both increase sedation. Use Caution/Monitor. - dexfenfluramine
chlorpheniramine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
dexfenfluramine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
dexfenfluramine and phenylephrine both decrease sedation. Use Caution/Monitor. - dexmedetomidine
dexmedetomidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and dexmedetomidine both increase sedation. Use Caution/Monitor.
dexmedetomidine and codeine both increase sedation. Use Caution/Monitor. - dexmethylphenidate
dexmethylphenidate and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
dexmethylphenidate and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - dextroamphetamine
dextroamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.
codeine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
dextroamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dextromoramide
chlorpheniramine and dextromoramide both increase sedation. Use Caution/Monitor.
codeine and dextromoramide both increase sedation. Use Caution/Monitor.
dextromoramide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - diamorphine
chlorpheniramine and diamorphine both increase sedation. Use Caution/Monitor.
codeine and diamorphine both increase sedation. Use Caution/Monitor.
diamorphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - diazepam
chlorpheniramine and diazepam both increase sedation. Use Caution/Monitor.
diazepam and codeine both increase sedation. Use Caution/Monitor. - diethylpropion
diethylpropion and phenylephrine both decrease sedation. Use Caution/Monitor.
diethylpropion and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - diazepam intranasal
diazepam intranasal, chlorpheniramine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
- diethylpropion
codeine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diethylpropion
chlorpheniramine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- difelikefalin
difelikefalin and codeine both increase sedation. Use Caution/Monitor.
difelikefalin and chlorpheniramine both increase sedation. Use Caution/Monitor. - difenoxin hcl
difenoxin hcl increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and difenoxin hcl both increase sedation. Use Caution/Monitor.
codeine and difenoxin hcl both increase sedation. Use Caution/Monitor. - dimenhydrinate
dimenhydrinate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and dimenhydrinate both increase sedation. Use Caution/Monitor.
dimenhydrinate and codeine both increase sedation. Use Caution/Monitor. - diphenhydramine
diphenhydramine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
diphenhydramine and codeine both increase sedation. Use Caution/Monitor.
diphenhydramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and diphenhydramine both increase sedation. Use Caution/Monitor. - diphenoxylate hcl
codeine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
chlorpheniramine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
diphenoxylate hcl increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - dipipanone
chlorpheniramine and dipipanone both increase sedation. Use Caution/Monitor.
codeine and dipipanone both increase sedation. Use Caution/Monitor.
dipipanone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - dobutamine
codeine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
dobutamine and phenylephrine both decrease sedation. Use Caution/Monitor.
dobutamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - donepezil transdermal
donepezil transdermal, chlorpheniramine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.
- dopamine
dopamine and phenylephrine both decrease sedation. Use Caution/Monitor.
dopamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dopamine
codeine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dopamine
chlorpheniramine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dopexamine
dopexamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
dopexamine and phenylephrine both decrease sedation. Use Caution/Monitor.
codeine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - dosulepin
chlorpheniramine and dosulepin both increase sedation. Use Caution/Monitor.
codeine and dosulepin both increase sedation. Use Caution/Monitor. - doxepin
doxepin increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- doxepin
codeine and doxepin both increase sedation. Use Caution/Monitor.
chlorpheniramine and doxepin both increase sedation. Use Caution/Monitor. - doxylamine
doxylamine and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and doxylamine both increase sedation. Use Caution/Monitor. - dronedarone
dronedarone decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- droperidol
droperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and droperidol both increase sedation. Use Caution/Monitor. - droperidol
codeine and droperidol both increase sedation. Use Caution/Monitor.
- droxidopa
phenylephrine and droxidopa both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. May increase risk for supine hypertension
- duloxetine
duloxetine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- efavirenz
efavirenz will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- elagolix
elagolix will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of codeine 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
ephedrine, phenylephrine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.
ephedrine and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
ephedrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epinephrine
epinephrine and phenylephrine both decrease sedation. Use Caution/Monitor.
codeine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
epinephrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epinephrine inhaled
phenylephrine, epinephrine inhaled. Either increases effects of the other by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- epinephrine racemic
chlorpheniramine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - epinephrine racemic
epinephrine racemic and phenylephrine both decrease sedation. Use Caution/Monitor.
epinephrine racemic and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - esketamine intranasal
esketamine intranasal, chlorpheniramine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
esketamine intranasal, codeine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. - estazolam
estazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
estazolam and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and estazolam both increase sedation. Use Caution/Monitor. - ethanol
ethanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and ethanol both increase sedation. Use Caution/Monitor.
codeine and ethanol both increase sedation. Use Caution/Monitor. - etomidate
etomidate and chlorpheniramine both increase sedation. Use Caution/Monitor.
etomidate and codeine both increase sedation. Use Caution/Monitor. - fenfluramine
fenfluramine and phenylephrine both decrease sedation. Use Caution/Monitor.
fenfluramine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - fedratinib
fedratinib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
fedratinib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary. - fenfluramine
chlorpheniramine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - fentanyl
fentanyl, chlorpheniramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- flibanserin
codeine and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.
- fentanyl intranasal
fentanyl intranasal, chlorpheniramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fentanyl transdermal
fentanyl transdermal, chlorpheniramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- fentanyl transmucosal
fentanyl transmucosal, chlorpheniramine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with anticholinergics may increase risk for urinary retention and/or severe constipation, which may lead to paralytic ileus.
- flibanserin
chlorpheniramine and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.
- fluoxetine
fluoxetine 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
- fluphenazine
fluphenazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and fluphenazine both increase sedation. Use Caution/Monitor.
fluphenazine, 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.
codeine and fluphenazine both increase sedation. Use Caution/Monitor. - flurazepam
chlorpheniramine and flurazepam both increase sedation. Use Caution/Monitor.
flurazepam and codeine both increase sedation. Use Caution/Monitor.
flurazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - formoterol
chlorpheniramine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
formoterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
formoterol and phenylephrine both decrease sedation. Use Caution/Monitor. - fosphenytoin
fosphenytoin will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- haloperidol
haloperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- gabapentin
gabapentin, codeine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- gabapentin
gabapentin, chlorpheniramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- gabapentin enacarbil
gabapentin enacarbil, codeine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
gabapentin enacarbil, chlorpheniramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation. - ganaxolone
codeine and ganaxolone both increase sedation. Use Caution/Monitor.
chlorpheniramine and ganaxolone both increase sedation. Use Caution/Monitor. - glycopyrronium tosylate topical
glycopyrronium tosylate topical, chlorpheniramine. 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.
- haloperidol
haloperidol decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
codeine and haloperidol both increase sedation. Use Caution/Monitor. - gotu kola
gotu kola increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- haloperidol
chlorpheniramine and haloperidol both increase sedation. Use Caution/Monitor.
- hawthorn
hawthorn increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hops
hops increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hyaluronidase
chlorpheniramine decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Antihistamines, when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients may require larger amounts of hyaluronidase for equivalent dispersing effect.
- hydralazine
hydralazine, phenylephrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.
- hydromorphone
chlorpheniramine and hydromorphone both increase sedation. Use Caution/Monitor.
hydromorphone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and hydromorphone both increase sedation. Use Caution/Monitor. - hydroxyzine
chlorpheniramine and hydroxyzine both increase sedation. Use Caution/Monitor.
hydroxyzine and codeine both increase sedation. Use Caution/Monitor.
hydroxyzine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - iloperidone
codeine and iloperidone both increase sedation. Use Caution/Monitor.
chlorpheniramine and iloperidone both increase sedation. Use Caution/Monitor.
iloperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
iloperidone increases levels of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4. - imipramine
codeine and imipramine both increase sedation. Use Caution/Monitor.
chlorpheniramine and imipramine both increase sedation. Use Caution/Monitor.
imipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
imipramine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine. - indacaterol, inhaled
phenylephrine increases effects of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: If additional adrenergic drugs are to be administered by any route, they should be used with caution because the sympathetic effects of indacaterol may be potentiated.
- isoniazid
isoniazid decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- insulin degludec
phenylephrine decreases effects of insulin degludec by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.
- insulin degludec/insulin aspart
phenylephrine decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.
- insulin inhaled
phenylephrine decreases effects of insulin inhaled by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.
- isoproterenol
isoproterenol and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
isoproterenol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - isoproterenol
codeine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ketotifen, ophthalmic
ketotifen, ophthalmic increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- istradefylline
istradefylline will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
- kava
kava increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- ketamine
ketamine and codeine both increase sedation. Use Caution/Monitor.
ketamine and chlorpheniramine both increase sedation. Use Caution/Monitor. - ketoconazole
ketoconazole decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- ketotifen, ophthalmic
chlorpheniramine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- ketotifen, ophthalmic
codeine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- lasmiditan
lasmiditan, chlorpheniramine. 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.
lasmiditan, codeine. 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, codeine. 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.
lemborexant, chlorpheniramine. 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. - lenacapavir
lenacapavir will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.
- letermovir
letermovir increases levels of codeine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- letermovir
letermovir increases levels of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- levalbuterol
levalbuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
levalbuterol and phenylephrine both decrease sedation. Use Caution/Monitor.
codeine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - levoketoconazole
levoketoconazole decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- levorphanol
levorphanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- levorphanol
chlorpheniramine and levorphanol both increase sedation. Use Caution/Monitor.
- levorphanol
codeine and levorphanol both increase sedation. Use Caution/Monitor.
- lisdexamfetamine
lisdexamfetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
lisdexamfetamine and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - lofepramine
chlorpheniramine and lofepramine both increase sedation. Use Caution/Monitor.
codeine and lofepramine both increase sedation. Use Caution/Monitor.
lofepramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - lofexidine
codeine and lofexidine both increase sedation. Use Caution/Monitor.
chlorpheniramine and lofexidine both increase sedation. Use Caution/Monitor.
lofexidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - lopinavir
lopinavir decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- loprazolam
loprazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- loprazolam
chlorpheniramine and loprazolam both increase sedation. Use Caution/Monitor.
- loprazolam
loprazolam and codeine both increase sedation. Use Caution/Monitor.
- lorazepam
lorazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and lorazepam both increase sedation. Use Caution/Monitor.
lorazepam and codeine both increase sedation. Use Caution/Monitor. - lorcaserin
lorcaserin will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- lormetazepam
lormetazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lormetazepam
chlorpheniramine and lormetazepam both increase sedation. Use Caution/Monitor.
- lormetazepam
lormetazepam and codeine both increase sedation. Use Caution/Monitor.
- loxapine
chlorpheniramine and loxapine both increase sedation. Use Caution/Monitor.
codeine and loxapine both increase sedation. Use Caution/Monitor.
loxapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - loxapine inhaled
loxapine inhaled increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and loxapine inhaled both increase sedation. Use Caution/Monitor.
chlorpheniramine and loxapine inhaled both increase sedation. Use Caution/Monitor. - lumefantrine
lumefantrine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- maprotiline
maprotiline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lurasidone
lurasidone, chlorpheniramine. 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.
- lurasidone
lurasidone, codeine. 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
chlorpheniramine and maprotiline both increase sedation. Use Caution/Monitor.
codeine and maprotiline both increase sedation. Use Caution/Monitor. - marijuana
chlorpheniramine and marijuana both increase sedation. Use Caution/Monitor.
marijuana increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and marijuana both increase sedation. Use Caution/Monitor. - melatonin
melatonin increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and melatonin both increase sedation. Use Caution/Monitor.
codeine and melatonin both increase sedation. Use Caution/Monitor. - meperidine
codeine and meperidine both increase sedation. Use Caution/Monitor.
chlorpheniramine and meperidine both increase sedation. Use Caution/Monitor.
meperidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - meprobamate
meprobamate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and meprobamate both increase sedation. Use Caution/Monitor.
chlorpheniramine and meprobamate both increase sedation. Use Caution/Monitor. - metaproterenol
metaproterenol and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
metaproterenol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - metaxalone
chlorpheniramine and metaxalone both increase sedation. Use Caution/Monitor.
metaxalone and codeine both increase sedation. Use Caution/Monitor. - methadone
methadone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- methadone
chlorpheniramine and methadone both increase sedation. Use Caution/Monitor.
codeine and methadone both increase sedation. Use Caution/Monitor. - methamphetamine
methamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
methamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor. - methocarbamol
chlorpheniramine and methocarbamol both increase sedation. Use Caution/Monitor.
methocarbamol and codeine both increase sedation. Use Caution/Monitor. - methyldopa
methyldopa increases effects of phenylephrine by unknown mechanism. Use Caution/Monitor.
- methylenedioxymethamphetamine
chlorpheniramine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
methylenedioxymethamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
methylenedioxymethamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor. - midazolam
midazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and midazolam both increase sedation. Use Caution/Monitor.
midazolam and codeine both increase sedation. Use Caution/Monitor. - midazolam intranasal
midazolam intranasal, codeine. 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.
midazolam intranasal, chlorpheniramine. 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
midodrine and phenylephrine both decrease sedation. Use Caution/Monitor.
midodrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - midodrine
codeine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - mirabegron
mirabegron will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- mirtazapine
chlorpheniramine and mirtazapine both increase sedation. Use Caution/Monitor.
mirtazapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - mirtazapine
codeine and mirtazapine both increase sedation. Use Caution/Monitor.
- modafinil
modafinil and phenylephrine both decrease sedation. Use Caution/Monitor.
- mitotane
mitotane decreases levels of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.
- modafinil
codeine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - morphine
chlorpheniramine and morphine both increase sedation. Use Caution/Monitor.
codeine and morphine both increase sedation. Use Caution/Monitor.
morphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - motherwort
chlorpheniramine and motherwort both increase sedation. Use Caution/Monitor.
codeine and motherwort both increase sedation. Use Caution/Monitor.
motherwort increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - moxonidine
codeine and moxonidine both increase sedation. Use Caution/Monitor.
moxonidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and moxonidine both increase sedation. Use Caution/Monitor. - nabilone
codeine and nabilone both increase sedation. Use Caution/Monitor.
chlorpheniramine and nabilone both increase sedation. Use Caution/Monitor.
nabilone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - nadolol
nadolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).
- nalbuphine
codeine and nalbuphine both increase sedation. Use Caution/Monitor.
chlorpheniramine and nalbuphine both increase sedation. Use Caution/Monitor. - nalbuphine
nalbuphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- norepinephrine
norepinephrine and phenylephrine both decrease sedation. Use Caution/Monitor.
codeine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
norepinephrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
chlorpheniramine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - nortriptyline
codeine and nortriptyline both increase sedation. Use Caution/Monitor.
chlorpheniramine and nortriptyline both increase sedation. Use Caution/Monitor.
nortriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - olanzapine
codeine and olanzapine both increase sedation. Use Caution/Monitor.
chlorpheniramine and olanzapine both increase sedation. Use Caution/Monitor.
olanzapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - oliceridine
oliceridine, codeine. 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.
- olodaterol inhaled
phenylephrine and olodaterol inhaled both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Caution with coadministration of adrenergic drugs by any route because of additive sympathetic effects
- opium tincture
chlorpheniramine and opium tincture both increase sedation. Use Caution/Monitor.
opium tincture increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - opium tincture
codeine and opium tincture both increase sedation. Use Caution/Monitor.
- oxazepam
oxazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- orphenadrine
orphenadrine and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and orphenadrine both increase sedation. Use Caution/Monitor. - oxazepam
oxazepam and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and oxazepam both increase sedation. Use Caution/Monitor. - oxycodone
oxycodone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and oxycodone both increase sedation. Use Caution/Monitor.
codeine and oxycodone both increase sedation. Use Caution/Monitor. - oxymetazoline topical
oxymetazoline topical and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- oxymorphone
codeine and oxymorphone both increase sedation. Use Caution/Monitor.
chlorpheniramine and oxymorphone both increase sedation. Use Caution/Monitor. - oxymorphone
oxymorphone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- oxytocin
oxytocin increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor.
- paliperidone
chlorpheniramine and paliperidone both increase sedation. Use Caution/Monitor.
paliperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and paliperidone both increase sedation. Use Caution/Monitor. - papaveretum
codeine and papaveretum both increase sedation. Use Caution/Monitor.
chlorpheniramine and papaveretum both increase sedation. Use Caution/Monitor.
papaveretum increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - papaverine
chlorpheniramine and papaverine both increase sedation. Use Caution/Monitor.
codeine and papaverine both increase sedation. Use Caution/Monitor. - pentazocine
pentazocine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- paroxetine
paroxetine 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.
- passion flower
passion flower increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- peginterferon alfa 2b
peginterferon alfa 2b, codeine. 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.
- pegvisomant
codeine decreases effects of pegvisomant by unknown mechanism. Use Caution/Monitor.
- pentazocine
chlorpheniramine and pentazocine both increase sedation. Use Caution/Monitor.
codeine and pentazocine both increase sedation. Use Caution/Monitor. - pentobarbital
pentobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and pentobarbital both increase sedation. Use Caution/Monitor.
pentobarbital and codeine both increase sedation. Use Caution/Monitor. - perampanel
perampanel and codeine both increase sedation. Use Caution/Monitor.
- perphenazine
perphenazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
perphenazine, 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. - perphenazine
chlorpheniramine and perphenazine both increase sedation. Use Caution/Monitor.
- perphenazine
codeine and perphenazine both increase sedation. Use Caution/Monitor.
- phendimetrazine
codeine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
phendimetrazine and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
phendimetrazine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - phenelzine
phenelzine increases effects of chlorpheniramine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- phenobarbital
phenobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenobarbital
phenobarbital and codeine both increase sedation. Use Caution/Monitor.
- phenobarbital
chlorpheniramine and phenobarbital both increase sedation. Use Caution/Monitor.
- phentermine
phentermine and phenylephrine both decrease sedation. Use Caution/Monitor.
chlorpheniramine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
phentermine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - phenylephrine
chlorpheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - pholcodine
pholcodine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenylephrine PO
codeine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
chlorpheniramine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. . - pholcodine
chlorpheniramine and pholcodine both increase sedation. Use Caution/Monitor.
codeine and pholcodine both increase sedation. Use Caution/Monitor. - pimozide
codeine and pimozide both increase sedation. Use Caution/Monitor.
pimozide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and pimozide both increase sedation. Use Caution/Monitor. - pindolol
pindolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).
- pirbuterol
codeine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - pirbuterol
pirbuterol and phenylephrine both decrease sedation. Use Caution/Monitor.
pirbuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - pregabalin
pregabalin, codeine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
pregabalin, chlorpheniramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation. - primidone
primidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and primidone both increase sedation. Use Caution/Monitor.
primidone and codeine both increase sedation. Use Caution/Monitor. - prochlorperazine
chlorpheniramine and prochlorperazine both increase sedation. Use Caution/Monitor.
codeine and prochlorperazine both increase sedation. Use Caution/Monitor.
prochlorperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
prochlorperazine, 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. - promazine
promazine, 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.
- promethazine
chlorpheniramine and promethazine both increase sedation. Use Caution/Monitor.
promethazine and codeine both increase sedation. Use Caution/Monitor. - promethazine
promethazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
promethazine, 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. - propofol
propofol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
propofol and chlorpheniramine both increase sedation. Use Caution/Monitor.
propofol and codeine both increase sedation. Use Caution/Monitor. - propranolol
propranolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).
- propylhexedrine
codeine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - propylhexedrine
phenylephrine and propylhexedrine both decrease sedation. Use Caution/Monitor.
phenylephrine and propylhexedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - protriptyline
chlorpheniramine and protriptyline both increase sedation. Use Caution/Monitor.
codeine and protriptyline both increase sedation. Use Caution/Monitor.
protriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - pseudoephedrine
phenylephrine and pseudoephedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- quazepam
chlorpheniramine and quazepam both increase sedation. Use Caution/Monitor.
quazepam and codeine both increase sedation. Use Caution/Monitor. - quazepam
quazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- quetiapine
quetiapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and quetiapine both increase sedation. Use Caution/Monitor.
chlorpheniramine and quetiapine both increase sedation. Use Caution/Monitor. - quinidine
quinidine 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.
- rasagiline
rasagiline increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode.
- ramelteon
chlorpheniramine and ramelteon both increase sedation. Use Caution/Monitor.
- ramelteon
codeine and ramelteon both increase sedation. Use Caution/Monitor.
- remimazolam
remimazolam, codeine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.
- ribociclib
ribociclib will increase the level or effect of codeine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- risperidone
codeine and risperidone both increase sedation. Use Caution/Monitor.
risperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and risperidone both increase sedation. Use Caution/Monitor. - ritonavir
ritonavir 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.
- safinamide
phenylephrine and safinamide both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Monitor patients for hypertension if safinamide is prescribed concomitantly with prescription or nonprescription sympathomimetics, including nasal, oral, or ophthalmic decongestants and cold remedies.
- rucaparib
rucaparib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.
- rolapitant
rolapitant will increase the level or effect of codeine 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.
- salmeterol
chlorpheniramine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
salmeterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
salmeterol and phenylephrine both decrease sedation. Use Caution/Monitor. - scullcap
codeine and scullcap both increase sedation. Use Caution/Monitor.
chlorpheniramine and scullcap both increase sedation. Use Caution/Monitor.
scullcap increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - secobarbital
secobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
secobarbital and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and secobarbital both increase sedation. Use Caution/Monitor. - selegiline
selegiline increases toxicity of codeine by unknown mechanism. Modify Therapy/Monitor Closely. Potential for increased CNS depression, drowsiness, dizziness or hypotension, so use with any MAOI should be cautious.
selegiline increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode. - serdexmethylphenidate/dexmethylphenidate
serdexmethylphenidate/dexmethylphenidate and phenylephrine both decrease sedation. Use Caution/Monitor.
serdexmethylphenidate/dexmethylphenidate and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - sertraline
sertraline decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- sevoflurane
sevoflurane and chlorpheniramine both increase sedation. Use Caution/Monitor.
sevoflurane and codeine both increase sedation. Use Caution/Monitor. - shepherd's purse
chlorpheniramine and shepherd's purse both increase sedation. Use Caution/Monitor.
codeine and shepherd's purse both increase sedation. Use Caution/Monitor.
shepherd's purse increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - solriamfetol
phenylephrine and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- stiripentol
stiripentol, codeine. 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.
stiripentol, chlorpheniramine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment. - sufentanil
sufentanil increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine and sufentanil both increase sedation. Use Caution/Monitor.
chlorpheniramine and sufentanil both increase sedation. Use Caution/Monitor. - suvorexant
suvorexant and codeine both increase sedation. Modify Therapy/Monitor Closely. Dosage adjustments of suvorexant and concomitant CNS depressants may be necessary
- tapentadol
tapentadol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tapentadol
chlorpheniramine and tapentadol both increase sedation. Use Caution/Monitor.
- tapentadol
codeine and tapentadol both increase sedation. Use Caution/Monitor.
- tazemetostat
tazemetostat will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tecovirimat
tecovirimat will decrease the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.
- temazepam
temazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and temazepam both increase sedation. Use Caution/Monitor.
temazepam and codeine both increase sedation. Use Caution/Monitor. - terbinafine
terbinafine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.
- terbutaline
terbutaline and phenylephrine both decrease sedation. Use Caution/Monitor.
terbutaline and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - terbutaline
chlorpheniramine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- terbutaline
codeine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- thioridazine
thioridazine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
codeine and thioridazine both increase sedation. Use Caution/Monitor.
thioridazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
thioridazine, 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.
chlorpheniramine and thioridazine both increase sedation. Use Caution/Monitor. - thiothixene
chlorpheniramine and thiothixene both increase sedation. Use Caution/Monitor.
codeine and thiothixene both increase sedation. Use Caution/Monitor.
thiothixene increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - ticlopidine
ticlopidine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- timolol
timolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).
- topiramate
topiramate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.
chlorpheniramine and topiramate both increase sedation. Modify Therapy/Monitor Closely. - topiramate
codeine and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- tramadol
tramadol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tramadol
chlorpheniramine and tramadol both increase sedation. Use Caution/Monitor.
codeine and tramadol both increase sedation. Use Caution/Monitor. - tranylcypromine
tranylcypromine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.
- trazodone
chlorpheniramine and trazodone both increase sedation. Use Caution/Monitor.
trazodone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - trazodone
codeine and trazodone both increase sedation. Use Caution/Monitor.
- triazolam
triazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- triazolam
chlorpheniramine and triazolam both increase sedation. Use Caution/Monitor.
triazolam and codeine both increase sedation. Use Caution/Monitor. - triclofos
triclofos and codeine both increase sedation. Use Caution/Monitor.
chlorpheniramine and triclofos both increase sedation. Use Caution/Monitor.
triclofos increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - trifluoperazine
chlorpheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.
codeine and trifluoperazine both increase sedation. Use Caution/Monitor.
trifluoperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
trifluoperazine, 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. - trimipramine
codeine and trimipramine both increase sedation. Use Caution/Monitor.
trimipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and trimipramine both increase sedation. Use Caution/Monitor. - triprolidine
triprolidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and triprolidine both increase sedation. Use Caution/Monitor.
triprolidine and codeine both increase sedation. Use Caution/Monitor. - valerian
valerian increases effects of chlorpheniramine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- xylometazoline
phenylephrine and xylometazoline both decrease sedation. Use Caution/Monitor.
phenylephrine and xylometazoline both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - venlafaxine
venlafaxine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- xylometazoline
chlorpheniramine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
codeine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - yohimbine
yohimbine and phenylephrine both decrease sedation. Use Caution/Monitor.
phenylephrine and yohimbine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
codeine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - ziconotide
codeine and ziconotide both increase sedation. Use Caution/Monitor.
chlorpheniramine and ziconotide both increase sedation. Use Caution/Monitor.
ziconotide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. - ziprasidone
codeine and ziprasidone both increase sedation. Use Caution/Monitor.
ziprasidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpheniramine and ziprasidone both increase sedation. Use Caution/Monitor. - zotepine
codeine and zotepine both increase sedation. Use Caution/Monitor.
chlorpheniramine and zotepine both increase sedation. Use Caution/Monitor.
Minor (36)
- acetazolamide
acetazolamide will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- alfuzosin
alfuzosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- anastrozole
anastrozole will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- asenapine
asenapine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
asenapine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown. - ashwagandha
ashwagandha increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- desmopressin
desmopressin increases effects of phenylephrine by pharmacodynamic synergism. Minor/Significance Unknown.
- brimonidine
brimonidine increases effects of codeine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.
brimonidine increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression. - cyclophosphamide
cyclophosphamide will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- dextroamphetamine
dextroamphetamine increases effects of codeine by unspecified interaction mechanism. Minor/Significance Unknown.
- doxazosin
doxazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- eucalyptus
eucalyptus increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.
codeine and eucalyptus both increase sedation. Minor/Significance Unknown.
chlorpheniramine and eucalyptus both increase sedation. Minor/Significance Unknown. - fluoxetine
fluoxetine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.
- moxisylyte
moxisylyte, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- larotrectinib
larotrectinib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- imatinib
imatinib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
imatinib decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine. - levoketoconazole
levoketoconazole will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- lidocaine
lidocaine increases toxicity of codeine by pharmacodynamic synergism. Minor/Significance Unknown. Risk of increased CNS depression.
- maraviroc
maraviroc will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- marijuana
marijuana will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- nettle
nettle increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.
- nilotinib
nilotinib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- parecoxib
parecoxib will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- perphenazine
perphenazine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
perphenazine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine. - phenoxybenzamine
phenoxybenzamine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- phentolamine
phentolamine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- prazosin
prazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- propafenone
propafenone will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
propafenone decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine. - quinacrine
quinacrine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
quinacrine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine. - ranolazine
ranolazine will increase the level or effect of codeine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
- ribociclib
ribociclib will increase the level or effect of chlorpheniramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
sage increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.
codeine and sage both increase sedation. Minor/Significance Unknown.
chlorpheniramine and sage both increase sedation. Minor/Significance Unknown. - Siberian ginseng
Siberian ginseng increases effects of chlorpheniramine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- silodosin
silodosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- sertraline
sertraline decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.
- terazosin
terazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- thioridazine
thioridazine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.
Adverse Effects
>10%
Codeine
- Drowsiness
- Constipation
1-10%
Codeine
- Bradycardia, hypotension, tachycardia
- Confusion, dizziness, false feeling of well being, headache, lightheadedness, malaise, paradoxical CNS stimulation, restlessness, weakness
- Rash, urticaria
- Anorexia, nausea, vomiting, xerostomia
- LFT's increased
- Ureteral spasm, urination decreased
- Dyspnea
- Burning at injection site, blurred vision, histamine release
Frequency Not Defined
Chlorpheniramine
- Anticholinergic
- Somnolence
- Constipation
- Diarrhea
- Nausea
- Vomiting
- Blurred vision
Codeine
- Hypotension, with IV use
- Seizure, with excessive doses
- Anaphylactoid reaction (rare)
- Respiratory depression
Phenylephrine
- Hypertension
- Severe peripheral and visceral vasoconstriction
- Pallor
- Reflex tachycardia
- Anxiety
- Dizziness
- Headache
- Insomnia,Nervousness
- Restlessness
- Metabolic acidosis
- Gastric irritation
- Nausea
- Decreased renal perfusion
- Extravasation of IV administration may lead to necrosis and sloughing of surrounding tissue
- Excitability
Warnings
Contraindications
Codeine
- Hypersensitivity
- Acute abdominal condition, diarrhea associated w/ toxins, pseudomembranous colitis, respiratory depression
- Asthma (acute), inflammatory bowel disease, respiratory impairment
Chlorpheniramine
- Acute asthma, sleep apnea
Phenylephrine
- Hypsesensitivity
- Severe HTN, severe CAD
- Within 14 days of nonselective MAO inhibitor therapy (risk of hypertensive reaction)
- Newborn, preemies
Cautions
Codeine
- Cardiac arrhythmias, drug abuse/dependence, emotional lability, gallbladder disease, head injury, hepatic impairment, hypothyroidism, increased ICP, prostatic hypertrophy, renal impairment, seizures with epilepsy, urethral stricture, urinary tract surgery
- Risk of life threatening side effects in nursing babies, especially if mother is an ultra rapid metabolizer of codeine
- Ibuprofen is more effective than codeine for pain from musculoskeletal injuries in children
Chlorpheniramine
- May cause CNS depression (patient should not operate heavy machinery
- Caution in patients with asthma, thyroid dysfunction, hypertension, ischemic heart disease, increased intraocular pressure, or prostatic hyperplasia/urinary obstruction
Phenylephrine
- Caution in diabetes mellitus, cardiovascular disease, prostatic hyperplasia, hyperthyroidism, and increased intraocular pressure
Pregnancy & Lactation
Pregnancy category: C
Not known whether distributed in breast milk, use caution
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Dihydrocodeine: Narcotic agonist analgesic with antitussive activity, mu receptor agonist
Chlorpheniramine: Histamine H1-receptor antagonist
Phenylephrine: Alpha-adrenergic stimulator with weak beta-adrenergic activity; produces systemic vasoconstriction of arteries and arterioles.
Codeine
Half-Life: 3-4 hr
Onset: 30-60 min
Metabolism: Inactive but metabolized to morphine by CYP2D6 (missing in 5-10% of population)
Duration: 4-6 hr
Peak Plasma Time: 0.5-1 hr
Vd: 3-6 L/kg
Bioavailability: 53%
Protein Bound: 25%
Excretion: Urine (90%), feces
Chlorpheniramine
Half-Life: 10-13 hr (children); 14-24 hr (adults)
Duration: 24 hr
Onset: 6 hr
Peak Plasma Time: 2-3 hr
Protein Bound: 29-37%
Vd: 4-7 L/kg (children); 6-12 L/kg (adults)
Metabolism: GI mucosa, liver
Metabolites: Monodesmethylchlorpheniramine, didesmethylchlorpheniramine
Excretion: Urine
Sedative effect: Low
Antihistamine activity: Moderate
Anticholinergic acitivity: Moderate
Phenylephrine
Half-Life: 2-3 hr
Duration: 2-4 hr
Onset: 10-15 min (IM/SC); immediate (IV)
Vd: 340 L (mean)
Bioavailability: < 38%
Peak Plasma Time: 0.75-2 hr
Metabolism: Hepatic
Excretion: Urine
Images
Formulary
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