Dosing & Uses
Dosage Forms & Strengths
tablet
- 1.34mg
- 2.68mg
syrup
- 0.67mg/5mL
Allergic Rhinitis
1.34 mg PO q12hr; not to exceed 8.04 mg/day for syrup or 2.68 mg/24 hours for tablets
Urticaria
2.68 mg PO qDay-q8hr; not to exceed 8.04 mg/day
Angioedema
2.68 mg PO qDay-q8hr; not to exceed 8.04 mg/day
Other Indications & Uses
Perennial & seasonal allergic & vasomotor rhinitis, relief of symptoms from colds, urticaria, angioedema, anaphylactic reactions, pruritus, allergic conjunctivitis
Dosage Forms & Strengths
tablet
- 1.34mg
- 2.68mg
syrup
- 0.67mg/5mL
Allergic Rhinitis
<6 years old: 0.05 mg/kg/day as clemastine base or 0.335-0.67 mg/day clemastine fumarate (0.25-0.5 mg base/day) divided q8-12hr; not to exceed 1.34 mg (1 mg base)
6-12 years old: 0.67-1.34 mg clemastine fumarate (0.5-1 mg base) q12hr; not to exceed 4.02 mg/day (3 mg/day base)
>12 years old: As in adults
Urticaria
<6 years old: 0.05 mg/kg/day as clemastine base or 0.335-0.67 mg/day clemastine fumarate (0.25-0.5 mg base/day) divided q8-12hr; not to exceed 1.34 mg (1 mg base)
6-12 years old: 0.67-1.34 mg clemastine fumarate (0.5-1 mg base) q12hr; not to exceed 4.02 mg/day (3 mg/day base)
>12 years old: As in adults
Administer lower doses to patients >60 years
Nonanticholinergic antihistamines should be considered first when treating allergic reactions (Beers Criteria)
Avoid use in elderly because of high incidence of anticholinergic effects
Clearance reduced with advanced age, greater risk of confusion, dry mouth, constipation, and other anticholinergic effects and toxicity
May exacerbate existing lower urinary conditions or benign prostatic hyperplasia
Allergic Rhinitis
1.34 mg PO q12hr; not to exceed 8.04 mg/day for syrup or 2.68 mg/24 hours for tablets
Urticaria
2.68 mg PO qDay-q8hr; not to exceed 8.04 mg/day
Angioedema
2.68 mg PO qDay-q8hr; not to exceed 8.04 mg/day
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (8)
- calcium/magnesium/potassium/sodium oxybates
clemastine, 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.
- eluxadoline
clemastine, 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.
- isocarboxazid
isocarboxazid increases effects of clemastine 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. .
- lonafarnib
clemastine will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
- metoclopramide intranasal
clemastine, 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.
- pitolisant
clemastine decreases effects of pitolisant by Other (see comment). Avoid or Use Alternate Drug. Comment: Pitolisant increases histamine levels in the brain; therefore, H1 receptor antagonists that cross the blood-brain barrier may reduce the efficacy of pitolisant.
- sodium oxybate
clemastine, 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.
- tranylcypromine
tranylcypromine increases effects of clemastine 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. .
Monitor Closely (208)
- albuterol
clemastine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- alfentanil
clemastine and alfentanil both increase sedation. Use Caution/Monitor.
- alprazolam
clemastine and alprazolam both increase sedation. Use Caution/Monitor.
- amifampridine
clemastine 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
clemastine and amitriptyline both increase sedation. Use Caution/Monitor.
- amobarbital
clemastine and amobarbital both increase sedation. Use Caution/Monitor.
- amoxapine
clemastine and amoxapine both increase sedation. Use Caution/Monitor.
- apomorphine
clemastine and apomorphine both increase sedation. Use Caution/Monitor.
- arformoterol
clemastine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- aripiprazole
clemastine and aripiprazole both increase sedation. Use Caution/Monitor.
- armodafinil
clemastine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- atogepant
clemastine will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- avapritinib
clemastine will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- axitinib
clemastine increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- azelastine
azelastine and clemastine both increase sedation. Use Caution/Monitor.
- baclofen
clemastine and baclofen both increase sedation. Use Caution/Monitor.
- belladonna and opium
clemastine and belladonna and opium both increase sedation. Use Caution/Monitor.
- benperidol
clemastine and benperidol both increase sedation. Use Caution/Monitor.
- benzphetamine
clemastine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- brexanolone
brexanolone, clemastine. Either increases toxicity of the other by sedation. Use Caution/Monitor.
- brompheniramine
brompheniramine and clemastine both increase sedation. Use Caution/Monitor.
- buprenorphine
clemastine and buprenorphine both increase sedation. Use Caution/Monitor.
- buprenorphine buccal
clemastine and buprenorphine buccal both increase sedation. Use Caution/Monitor.
- butabarbital
clemastine and butabarbital both increase sedation. Use Caution/Monitor.
- butalbital
clemastine and butalbital both increase sedation. Use Caution/Monitor.
- butorphanol
clemastine and butorphanol both increase sedation. Use Caution/Monitor.
- caffeine
clemastine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- carbinoxamine
carbinoxamine and clemastine both increase sedation. Use Caution/Monitor.
- carisoprodol
clemastine and carisoprodol both increase sedation. Use Caution/Monitor.
- cenobamate
cenobamate, clemastine. Either increases effects of the other by sedation. Use Caution/Monitor.
- chloral hydrate
clemastine and chloral hydrate both increase sedation. Use Caution/Monitor.
- chlordiazepoxide
clemastine and chlordiazepoxide both increase sedation. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine and clemastine both increase sedation. Use Caution/Monitor.
- chlorpromazine
clemastine and chlorpromazine both increase sedation. Use Caution/Monitor.
- chlorzoxazone
clemastine and chlorzoxazone both increase sedation. Use Caution/Monitor.
- cinnarizine
cinnarizine and clemastine both increase sedation. Use Caution/Monitor.
- clobazam
clemastine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
- clomipramine
clemastine and clomipramine both increase sedation. Use Caution/Monitor.
- clonazepam
clemastine and clonazepam both increase sedation. Use Caution/Monitor.
- clorazepate
clemastine and clorazepate both increase sedation. Use Caution/Monitor.
- clozapine
clemastine and clozapine both increase sedation. Use Caution/Monitor.
- codeine
clemastine and codeine both increase sedation. Use Caution/Monitor.
- cyclizine
clemastine and cyclizine both increase sedation. Use Caution/Monitor.
- cyclobenzaprine
clemastine and cyclobenzaprine both increase sedation. Use Caution/Monitor.
- cyproheptadine
clemastine and cyproheptadine both increase sedation. Use Caution/Monitor.
- dantrolene
clemastine and dantrolene both increase sedation. Use Caution/Monitor.
- daridorexant
clemastine 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.
- desflurane
desflurane and clemastine both increase sedation. Use Caution/Monitor.
- desipramine
clemastine and desipramine both increase sedation. Use Caution/Monitor.
- deutetrabenazine
clemastine and deutetrabenazine both increase sedation. Use Caution/Monitor.
- dexchlorpheniramine
clemastine and dexchlorpheniramine both increase sedation. Use Caution/Monitor.
- dexfenfluramine
clemastine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmedetomidine
clemastine and dexmedetomidine both increase sedation. Use Caution/Monitor.
- dexmethylphenidate
clemastine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dextroamphetamine
clemastine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dextromoramide
clemastine and dextromoramide both increase sedation. Use Caution/Monitor.
- diamorphine
clemastine and diamorphine both increase sedation. Use Caution/Monitor.
- diazepam
clemastine and diazepam both increase sedation. Use Caution/Monitor.
- diazepam intranasal
diazepam intranasal, clemastine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
- diethylpropion
clemastine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- difelikefalin
difelikefalin and clemastine both increase sedation. Use Caution/Monitor.
- difenoxin hcl
clemastine and difenoxin hcl both increase sedation. Use Caution/Monitor.
- dimenhydrinate
clemastine and dimenhydrinate both increase sedation. Use Caution/Monitor.
- diphenhydramine
clemastine and diphenhydramine both increase sedation. Use Caution/Monitor.
- diphenoxylate hcl
clemastine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
- dipipanone
clemastine and dipipanone both increase sedation. Use Caution/Monitor.
- dobutamine
clemastine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- donepezil transdermal
donepezil transdermal, clemastine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.
- dopamine
clemastine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dopexamine
clemastine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dosulepin
clemastine and dosulepin both increase sedation. Use Caution/Monitor.
- doxepin
clemastine and doxepin both increase sedation. Use Caution/Monitor.
- doxylamine
clemastine and doxylamine both increase sedation. Use Caution/Monitor.
- droperidol
clemastine and droperidol both increase sedation. Use Caution/Monitor.
- ephedrine
clemastine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- epinephrine
clemastine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- epinephrine racemic
clemastine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- esketamine intranasal
esketamine intranasal, clemastine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
- estazolam
clemastine and estazolam both increase sedation. Use Caution/Monitor.
- ethanol
clemastine and ethanol both increase sedation. Use Caution/Monitor.
- etomidate
etomidate and clemastine both increase sedation. Use Caution/Monitor.
- fenfluramine
clemastine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- fentanyl
fentanyl, clemastine. 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 intranasal
fentanyl intranasal, clemastine. 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, clemastine. 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, clemastine. 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.
- finerenone
clemastine will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.
- flibanserin
clemastine and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.
clemastine will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors. - fluphenazine
clemastine and fluphenazine both increase sedation. Use Caution/Monitor.
- flurazepam
clemastine and flurazepam both increase sedation. Use Caution/Monitor.
- formoterol
clemastine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- gabapentin
gabapentin, clemastine. 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, clemastine. 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
clemastine and ganaxolone both increase sedation. Use Caution/Monitor.
- glycopyrronium tosylate topical
glycopyrronium tosylate topical, clemastine. 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.
- gotu kola
gotu kola increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- haloperidol
clemastine and haloperidol both increase sedation. Use Caution/Monitor.
- hawthorn
hawthorn increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hops
hops increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hyaluronidase
clemastine 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.
- hydromorphone
clemastine and hydromorphone both increase sedation. Use Caution/Monitor.
- hydroxyzine
clemastine and hydroxyzine both increase sedation. Use Caution/Monitor.
- iloperidone
clemastine and iloperidone both increase sedation. Use Caution/Monitor.
- imipramine
clemastine and imipramine both increase sedation. Use Caution/Monitor.
- isavuconazonium sulfate
clemastine will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- isoproterenol
clemastine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ivacaftor
clemastine increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .
- kava
kava increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- ketamine
ketamine and clemastine both increase sedation. Use Caution/Monitor.
- ketotifen, ophthalmic
clemastine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- lasmiditan
lasmiditan, clemastine. 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
clemastine will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
lemborexant, clemastine. 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. - levalbuterol
clemastine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- levorphanol
clemastine and levorphanol both increase sedation. Use Caution/Monitor.
- lisdexamfetamine
clemastine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lofepramine
clemastine and lofepramine both increase sedation. Use Caution/Monitor.
- lofexidine
clemastine and lofexidine both increase sedation. Use Caution/Monitor.
- lomitapide
clemastine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- loprazolam
clemastine and loprazolam both increase sedation. Use Caution/Monitor.
- lorazepam
clemastine and lorazepam both increase sedation. Use Caution/Monitor.
- lormetazepam
clemastine and lormetazepam both increase sedation. Use Caution/Monitor.
- loxapine
clemastine and loxapine both increase sedation. Use Caution/Monitor.
- loxapine inhaled
clemastine and loxapine inhaled both increase sedation. Use Caution/Monitor.
- lurasidone
lurasidone, clemastine. 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
clemastine and maprotiline both increase sedation. Use Caution/Monitor.
- marijuana
clemastine and marijuana both increase sedation. Use Caution/Monitor.
- melatonin
clemastine and melatonin both increase sedation. Use Caution/Monitor.
- meperidine
clemastine and meperidine both increase sedation. Use Caution/Monitor.
- meprobamate
clemastine and meprobamate both increase sedation. Use Caution/Monitor.
- metaproterenol
clemastine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- metaxalone
clemastine and metaxalone both increase sedation. Use Caution/Monitor.
- methadone
clemastine and methadone both increase sedation. Use Caution/Monitor.
- methamphetamine
clemastine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- methocarbamol
clemastine and methocarbamol both increase sedation. Use Caution/Monitor.
- methylenedioxymethamphetamine
clemastine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- midazolam
clemastine and midazolam both increase sedation. Use Caution/Monitor.
- midazolam intranasal
clemastine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
midazolam intranasal, clemastine. 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
clemastine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- mirtazapine
clemastine and mirtazapine both increase sedation. Use Caution/Monitor.
- modafinil
clemastine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- morphine
clemastine and morphine both increase sedation. Use Caution/Monitor.
- motherwort
clemastine and motherwort both increase sedation. Use Caution/Monitor.
- moxonidine
clemastine and moxonidine both increase sedation. Use Caution/Monitor.
- nabilone
clemastine and nabilone both increase sedation. Use Caution/Monitor.
- nalbuphine
clemastine and nalbuphine both increase sedation. Use Caution/Monitor.
- norepinephrine
clemastine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nortriptyline
clemastine and nortriptyline both increase sedation. Use Caution/Monitor.
- olanzapine
clemastine and olanzapine both increase sedation. Use Caution/Monitor.
- opium tincture
clemastine and opium tincture both increase sedation. Use Caution/Monitor.
- orphenadrine
clemastine and orphenadrine both increase sedation. Use Caution/Monitor.
- oxazepam
clemastine and oxazepam both increase sedation. Use Caution/Monitor.
- oxycodone
clemastine and oxycodone both increase sedation. Use Caution/Monitor.
- oxymorphone
clemastine and oxymorphone both increase sedation. Use Caution/Monitor.
- paliperidone
clemastine and paliperidone both increase sedation. Use Caution/Monitor.
- papaveretum
clemastine and papaveretum both increase sedation. Use Caution/Monitor.
- papaverine
clemastine and papaverine both increase sedation. Use Caution/Monitor.
- passion flower
passion flower increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- pentazocine
clemastine and pentazocine both increase sedation. Use Caution/Monitor.
- pentobarbital
clemastine and pentobarbital both increase sedation. Use Caution/Monitor.
- perphenazine
clemastine and perphenazine both increase sedation. Use Caution/Monitor.
- phendimetrazine
clemastine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenelzine
phenelzine increases effects of clemastine 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
clemastine and phenobarbital both increase sedation. Use Caution/Monitor.
- phentermine
clemastine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenylephrine
clemastine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phenylephrine PO
clemastine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- pholcodine
clemastine and pholcodine both increase sedation. Use Caution/Monitor.
- pimozide
clemastine and pimozide both increase sedation. Use Caution/Monitor.
- pirbuterol
clemastine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pregabalin
pregabalin, clemastine. 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
clemastine and primidone both increase sedation. Use Caution/Monitor.
- prochlorperazine
clemastine and prochlorperazine both increase sedation. Use Caution/Monitor.
- promethazine
clemastine and promethazine both increase sedation. Use Caution/Monitor.
- propofol
propofol and clemastine both increase sedation. Use Caution/Monitor.
- propylhexedrine
clemastine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- protriptyline
clemastine and protriptyline both increase sedation. Use Caution/Monitor.
- quazepam
clemastine and quazepam both increase sedation. Use Caution/Monitor.
- quetiapine
clemastine and quetiapine both increase sedation. Use Caution/Monitor.
- ramelteon
clemastine and ramelteon both increase sedation. Use Caution/Monitor.
- risperidone
clemastine and risperidone both increase sedation. Use Caution/Monitor.
- salmeterol
clemastine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- scullcap
clemastine and scullcap both increase sedation. Use Caution/Monitor.
- secobarbital
clemastine and secobarbital both increase sedation. Use Caution/Monitor.
- sevoflurane
sevoflurane and clemastine both increase sedation. Use Caution/Monitor.
- shepherd's purse
clemastine and shepherd's purse both increase sedation. Use Caution/Monitor.
- stiripentol
stiripentol, clemastine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
- sufentanil
clemastine and sufentanil both increase sedation. Use Caution/Monitor.
- tapentadol
clemastine and tapentadol both increase sedation. Use Caution/Monitor.
- tazemetostat
clemastine will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- temazepam
clemastine and temazepam both increase sedation. Use Caution/Monitor.
- terbutaline
clemastine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- thioridazine
clemastine and thioridazine both increase sedation. Use Caution/Monitor.
- thiothixene
clemastine and thiothixene both increase sedation. Use Caution/Monitor.
- tinidazole
clemastine will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- topiramate
clemastine and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- tramadol
clemastine and tramadol both increase sedation. Use Caution/Monitor.
- trazodone
clemastine and trazodone both increase sedation. Use Caution/Monitor.
- triazolam
clemastine and triazolam both increase sedation. Use Caution/Monitor.
- triclofos
clemastine and triclofos both increase sedation. Use Caution/Monitor.
- trifluoperazine
clemastine and trifluoperazine both increase sedation. Use Caution/Monitor.
- trimipramine
clemastine and trimipramine both increase sedation. Use Caution/Monitor.
- triprolidine
clemastine and triprolidine both increase sedation. Use Caution/Monitor.
- valerian
valerian increases effects of clemastine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- xylometazoline
clemastine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- yohimbine
clemastine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ziconotide
clemastine and ziconotide both increase sedation. Use Caution/Monitor.
- ziprasidone
clemastine and ziprasidone both increase sedation. Use Caution/Monitor.
- zotepine
clemastine and zotepine both increase sedation. Use Caution/Monitor.
Minor (8)
- ashwagandha
ashwagandha increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- brimonidine
brimonidine increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.
- eucalyptus
clemastine and eucalyptus both increase sedation. Minor/Significance Unknown.
- nettle
nettle increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.
- ruxolitinib
clemastine will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ruxolitinib topical
clemastine will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
clemastine and sage both increase sedation. Minor/Significance Unknown.
- Siberian ginseng
Siberian ginseng increases effects of clemastine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
Adverse Effects
Varies in incidence & severity with the individual drug; also individual patients vary in susceptibility
Frequency Not Defined
CNS depression
Drowsiness
Sedation ranging from mild drowsiness to deep sleep (most frequent)
Dizziness
Lassitude
Disturbed coordination
Muscular weakness
Restlessness, insomnia, tremors, euphoria, nervousness, delirium, palpitation, seizures is less common
Epigastric distress
Anorexia
Nausea
Vomiting
Diarrhea
Constipation
Cholestasis, hepatitis, hepatic failure, hepatic function abnormality, jaundice is rare
Eczema, pruritus, inflammation, papular rash, erythema on exposed skin may occur with topical formulation
Tachycardia, palpitation ECG changes (eg, widened QRS) Arrhythmias (eg, extrasystole, heart block)
Hypotension
Hypertension
Dizziness, sedation, and hypotension may occur in geriatric patients
Dryness of mouth, nose, and throat
Dysuria
Urinary retention
Impotence
Vertigo
Visual disturbances
Blurred vision
Diplopia; tinnitus
Acute labyrinthitis
Insomnia
Tremors
Nervousness
Irritability
Facial dyskinesia
Tightness of the chest
Thickening of bronchial secretions
Wheezing
Nasal stuffiness
Sweating
Chills
Early menses
Toxic psychosis
Headache
Faintness
Paresthesia
Agranulocytosis
Hemolytic anemia
Leukopenia
Thrombocytopenia
Pancytopenia
Warnings
Contraindications
Documented hypersensitivity
Lower respiratory disease, eg, asthma (controversial)
Preemies & neonates
Nursing women
Caution
Caution in narrow angle glaucoma, prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, or bladder neck obstruction
Pregnancy & Lactation
Pregnancy Category: B
Lactation: enters breast milk/not recommended
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
Histamine H1-receptor antagonist in blood vessels, respiratory tract, and gastrointestinal tract
Pharmacokinetics
Onset: 5-7 hr
Duration: 8-12 hr
Peak Plasma Time: 2-5 hr
Vd: 800 L
Metabolism: Hepatic
Bioavailability: ~40%
Half-life elimination: 21 hr
Excretion: Urine
Sedation: Low to moderate
Antihistamine activity: Low to moderate
Anticholinergic activity: High
Antiemetic effects: Low to moderate
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| clemastine oral - | 2.68 mg tablet |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
clemastine oral
CLEMASTINE - ORAL
(KLEM-ast-een)
COMMON BRAND NAME(S): Tavist
USES: Clemastine is an antihistamine used to relieve symptoms of allergy, hay fever, and the common cold. These symptoms include rash, watery eyes, itchy eyes/nose/throat/skin, cough, runny nose, and sneezing. This medication works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. By blocking another natural substance made by your body (acetylcholine), it helps dry up some body fluids to relieve symptoms such as watery eyes and runny nose.Cough-and-cold products have not been shown to be safe or effective in children younger than 6 years. Do not use this product to treat cold symptoms in children younger than 6 years unless specifically directed by the doctor. Some products (such as long-acting tablets/capsules) are not recommended for use in children younger than 12 years. Ask your doctor or pharmacist for more details about using your product safely.These products do not cure or shorten the length of the common cold and may cause serious side effects. To decrease the risk for serious side effects, carefully follow all dosage directions. Do not use this product to make a child sleepy. Do not give other cough-and-cold medication that might contain the same or similar ingredients (see also Drug Interactions section). Ask the doctor or pharmacist about other ways to relieve cough and cold symptoms (such as drinking enough fluids, using a humidifier or saline nose drops/spray).
HOW TO USE: If you are taking the over-the-counter product, read all directions on the product package before taking this medication. If you have any questions, consult your pharmacist. If your doctor has prescribed this medication, take it as directed.Take the tablet or liquid form by mouth with or without food. Follow the directions for dosing on the label, or take as directed by your doctor. This medication may be taken with food or milk if stomach upset occurs.If you are using the liquid form of this medication, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.Your dosage is based on your age, medical condition, and response to therapy. Do not increase your dose or take this medication more often than recommended by your doctor or the package instructions without your doctor's approval. Take this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time(s) each day.If your condition lasts or gets worse, or if you think you may have a serious medical problem, get medical help right away.
SIDE EFFECTS: Drowsiness, dizziness, headache, constipation, stomach upset, blurred vision, trouble walking/clumsiness, or dry mouth/nose/throat may occur. These effects may decrease as your body adjusts to the medication. If any of these effects last or get worse, contact your doctor or pharmacist promptly.To relieve dry mouth, suck on (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute. Clemastine can dry up and thicken mucus in your lungs, making it more difficult to breathe and clear your lungs. To help prevent this effect, drink plenty of fluids unless otherwise directed by your doctor.If your doctor has prescribed this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as hallucinations, irritability, nervousness, confusion), ringing in the ears, trouble urinating, easy bruising/bleeding, fast/irregular heartbeat, seizure.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking clemastine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as asthma, emphysema), a certain eye problem (glaucoma), heart problems, high blood pressure, liver disease, seizures, stomach problems (such as ulcers, blockage), overactive thyroid (hyperthyroidism), urination problems (such as trouble urinating due to enlarged prostate, urinary retention).This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.Liquid preparations of this product may contain sugar and/or alcohol. Caution is advised if you have diabetes, alcohol dependence, or liver disease. Ask your doctor or pharmacist about the safe use of this product.Older adults may be more sensitive to the side effects of this drug, especially drowsiness, constipation, problems urinating, or confusion. Drowsiness and confusion can increase the risk of falling.Children may be more sensitive to the effects of antihistamines. In young children, this medication may cause agitation/excitement instead of drowsiness.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray).Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as cetirizine, diphenhydramine).Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: large pupils, flushing, fever, hallucinations, weakness, shaking (tremor), muscle twitching, loss of consciousness, seizures. In children, excitement may occur first, and may be followed by loss of coordination, drowsiness, loss of consciousness, seizures.
NOTES: If your doctor has prescribed this medication, do not share it with others.Keep all regular medical and laboratory appointments.Do not take for several days before allergy testing because test results can be affected.
MISSED DOSE: If you are taking this medication on a regular schedule and miss a dose, take it as soon as you remember. If it is near the time of your next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Do not freeze liquid forms of this medication. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised March 2022. Copyright(c) 2022 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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- View the formulary and any restrictions for each plan.
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