Chlorpheniramine Maleate

Pronunciation: (klor-fen-AIR-uh-meen MAL-ee-ate)Class: Alkylamine, nonselective

Trade Names:Aller-Chlor- Tablets 4 mg- Syrup 2 mg per 5 mL

Trade Names:Allergy- Tablets 4 mg

Trade Names:Allergy Relief- Tablets 4 mg

Trade Names:Chlor-Trimeton- Tablets 4 mg

Trade Names:Chlor-Trimeton Allergy 8 Hour- Tablets, extended-release 8 mg

Trade Names:Chlor-Trimeton Allergy 12 Hour- Tablets, extended-release 12 mg

Trade Names:Chlorpheniramine Maleate- Capsules, sustained-release 8 mg- Capsules, sustained-release 12 mg

Trade Names:Chlorpheniramine Maleate- Tablets 4 mg

Chlor-Tripolon (Canada)


Competitively antagonizes histamine at H 1 receptor sites.



Readily absorbed.


72% protein bound.


Metabolized predominantly in the liver, but also in the lung and kidneys.


Renally eliminated, mostly as metabolites within 24 h.

Indications and Usage

Temporary relief of sneezing, itchy, watery eyes, itchy nose or throat, and runny nose caused by hay fever (allergic rhinitis), or other respiratory allergies.


Hypersensitivity to antihistamines; narrow-angle glaucoma; stenosing peptic ulcer; symptomatic prostatic hypertrophy; asthmatic attack; bladder neck obstruction; pyloroduodenal obstruction; MAO therapy; use in newborn or premature infants and in breast-feeding mothers.

Dosage and Administration

Immediate-release tablet or syrupAdults and children 12 yr of age and older

PO 4 mg every 4 to 6 h (max, 24 mg/day).

Children 6 to younger than 12 yr of age

PO 2 mg every 4 to 6 h (max, 12 mg/day).

Children younger than 5 yr of age

PO As recommended by health care provider.

Extended-release tabletsAdults and children 12 yr of age and older

PO 8 mg every 8 to 12 h or 12 mg every 12 h (max, 24 mg/day).

Extended-release capsulesAdults and children 12 yr of age and older

PO 8 or 12 mg in the morning and evening (max, 24 mg/day).

General Advice

  • Administer without regard to meals. Administer with food if GI upset occurs.
  • Measure and administer prescribed dose of oral syrup using dosing syringe, dosing spoon, or dosing cup.
  • Advise patient receiving extended-release tablets or sustained-release capsules to swallow tablets or capsules whole and not to crush, chew, break, or open.


Store all dose forms at controlled room temperature (59° to 86°F).

Drug Interactions

Alcohol, CNS depressants, and tricyclic antidepressants

May cause additive CNS depressant effects.


May increase anticholinergic effects of chlorpheniramine.

Ototoxic medications

Concurrent use may mask the symptoms of ototoxicity.

Laboratory Test Interactions

Skin testing procedures

Antihistamines may prevent or diminish otherwise positive reaction to dermal reactivity indicators.

Adverse Reactions


Bradycardia; extrasystoles; orthostatic hypotension; palpitations; reflex tachycardia; tachycardia.


Confusion; convulsions; disturbed coordination; dizziness; drowsiness; euphoria; excitation; faintness; fatigue; headache; hysteria; insomnia; irritability; nervousness; neuritis; paresthesias; restlessness; sedation; tremor; vertigo.


Acute labyrinthitis; blurred vision; diplopia; dry nose and throat; nasal stuffiness; sore throat; tinnitus.


Anorexia; constipation; diarrhea; dry mouth; epigastric distress; nausea; vomiting.


Difficult urination; dysuria; early menses; urinary frequency or retention.


Agranulocytosis; hemolytic anemia; thrombocytopenia.


Increased appetite; weight gain.


Chest tightness; respiratory depression; thickening of bronchial secretions; wheezing.


Chills; excessive perspiration; hypersensitivity reactions; photosensitivity.



Allergy symptoms

Assess allergy symptoms (eg, cough, rhinitis, nasal congestion, sneezing, watery eyes, or itching nose, throat, or eyes) before starting therapy and periodically during therapy. Notify health care provider if symptoms are not improving or are getting worse.


Monitor patient for dizziness and excessive drowsiness. If noted, hold therapy and notify health care provider.

Review therapy

Ensure therapy periodically is reviewed to determine if it needs to be continued without change or if a dose change (eg, increase, decrease, discontinuation) is indicated.


Category C . Do not use during third trimester.


Contraindicated in breast-feeding mothers.


Overdosage may cause hallucinations, convulsions, and death. Antihistamines may diminish mental alertness. In young children, they may produce paradoxical excitation. Contraindicated in newborn or premature infants. Sustained-release form not recommended in children younger than 12 yr of age.


Use with caution, usually starting at the low end of the dosage range because of the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy.


May occur. Have epinephrine 1:1,000 immediately available.

Hepatic Function

Use drug with caution in patients with cirrhosis or other liver disease.

Special Risk Patients

Use drug with caution in patients with predisposition to urinary retention, history of bronchial asthma, increased IOP, hyperthyroidism, CV disease, or hypertension. Avoid in patients with sleep apnea.

RESP disease

Generally not recommended to treat lower respiratory tract symptoms, including asthma.



CNS depression (including sedation, apnea, CV collapse), CNS stimulation (including insomnia, hallucination, tremors, convulsions), tinnitus, blurred vision, dizziness, ataxia, hypotension. Stimulation and atropine-like signs and symptoms (including dry mouth, fixed dilated pupils, flushing, hyperthermia, GI symptoms) are more likely in children.

Patient Information

  • Caution patient using OTC chlorpheniramine that each product has specific dosing instructions and to read package label before using and not to exceed dose or frequency of administration instructions.
  • Advise patient to take each dose without regard to meals, but to take with food if stomach upset occurs.
  • Advise patient or caregiver using oral syrup to measure and administer prescribed dose using dosing syringe, dosing spoon, or dosing cup.
  • Advise patient that if a dose is missed, to take it as soon as possible unless it is nearing time for the next scheduled dose. If it is nearing time for next scheduled dose, advise patient to skip the missed dose and take the next dose at the regularly scheduled time. Caution patient not to double the dose to catch up.
  • Advise patient that if allergy symptoms are not controlled, not to increase the dose of medication or frequency of use but to inform health care provider. Caution patient that larger doses or more frequent dosing does not increase efficacy and may cause excessive drowsiness or other adverse reactions.
  • Instruct patient to stop taking drug and immediately report any of these symptoms to health care provider: persistent dizziness; excessive drowsiness; severe dry mouth, nose, or throat; flushing; unexplained shortness of breath or difficulty breathing; unusual tiredness or weakness; sore throat, fever, or other signs of infection; bleeding or unusual bruising; fast or irregular heartbeat; excitability, confusion, or changes in thinking or behavior; chest tightness; difficulty with urination.
  • Advise patient medication may cause drowsiness or dizziness and not to drive or perform other activities requiring mental alertness until tolerance is determined.
  • Advise patient to take sips of water, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.
  • Caution patient alcohol and other CNS depressants (eg, sedatives) will have additional sedative effects if taken with chlorpheniramine.
  • Caution patient not to take any other OTC antihistamines while taking this medication unless advised by health care provider.
  • Caution patient that medication may cause sensitivity to sunlight and to avoid excessive exposure to the sun or UV light (eg, tanning booths) and to wear protective clothing and use sunscreens until tolerance is determined.
  • If patient is to have allergy skin testing, advise patient not to take the medication for at least 4 days before the skin testing.

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