Home > Medical Reference > Encyclopedia (English)

Please install flash player to see this video.

Hospital Virtual Tour

Related Content

Pronunciation:

(klor fen IR a meen, fen il EF rin, & meth skoe POL a meen)

U.S. Brand Names:

AH-Chew®; AH-Chew II; Chlor-Mes-D; Dallergy®; Dehistine; Drize®-R; Extendryl; Extendryl JR; Extendryl SR; Hista-Vent® DA; PCM; PCM Allergy; Vanex Forte™-D [DSC]

Synonyms:

Methscopolamine, Chlorpheniramine, and Phenylephrine; Phenylephrine, Chlorpheniramine, and Methscopolamine

Generic Available:

Yes

Use:

Treatment of upper respiratory symptoms such as respiratory congestion, allergic rhinitis, vasomotor rhinitis, sinusitis, and allergic skin reactions of urticaria and angioedema

Pregnancy Risk Factor:

Pregnancy Implications:

Reproduction studies with this combination have not been conducted; see individual agents.

Lactation:

Phenylephrine enters breast milk; excretion of chlorpheniramine or methscopolamine in breast milk is unknown. See individual agents.

Contraindications:

Hypersensitivity to chlorpheniramine, methscopolamine, phenylephrine, or any component of the formulation; patients with severe hypertension, severe coronary artery disease, narrow-angle glaucoma, urinary retention, peptic ulcer, hyperthyroidism; patients on MAO inhibitors or beta-blockers; not for use during asthma exacerbation

Warnings/Precautions:

Use with caution in patients with hypertension, diabetes mellitus, ischemic heart disease, increased intraocular pressure, and prostatic hyperplasia. Elderly patients may be more likely to exhibit adverse reactions; use with caution in patients >40 years. May cause excitability in some patients, especially children. If disturbances in urination occur, discontinue medication for 1-2 days and restart at lower dosage. Safety and efficacy in children <6 years have not been established.

Adverse Reactions:

Frequency not defined.

Cardiovascular: Arrhythmias, bradycardia, cardiovascular collapse, flushing, hypotension, pallor, palpitation, tachycardia

Central nervous system: Anxiety, convulsions, CNS depression, dizziness, drowsiness, excitability, fear, giddiness, hallucinations, headache, insomnia, irritability, lassitude, restlessness, tenseness, tremor

Gastrointestinal: Constipation, dysphagia, gastric irritation, nausea, xerostomia

Genitourinary: Dysuria, urinary retention

Neuromuscular & skeletal: Weakness

Ocular: Blurred vision, mydriasis

Respiratory: Dry nose, dry throat, respiratory difficulty

Overdosage/Toxicology:

Treatment is symptom-directed and supportive. If convulsions or marked CNS excitement occur, short-acting benzodiazepines may be used.

Drug Interactions:

Chlorpheniramine: Substrate of CYP2D6 (minor), 3A4 (major); Inhibits CYP2D6 (weak)

Also see individual agents.

Antihistamines: Additive effects would be expected with concomitant use

Beta blockers: May lead to increased sympathomimetic effects (phenylephrine); concomitant use is contraindicated

MAO inhibitors: May lead to increased sympathomimetic effects (phenylephrine); concomitant use is contraindicated

Mecamylamine: Decreased antihypertensive effects with concomitant use

Methyldopa: Decreased antihypertensive effects with concomitant use

Reserpine: Decreased antihypertensive effects with concomitant use

Ethanol/Nutrition/Herb Interactions:

Ethanol: Avoid ethanol (increased CNS depression).

Stability:

Store at controlled room temperature

Mechanism of Action:

Chlorpheniramine maleate: Antihistamine

Phenylephrine hydrochloride: Sympathomimetic agent (primarily alpha), decongestant

Methscopolamine nitrate: Derivative of scopolamine, antisecretory effects

Pharmacodynamics/Kinetics:

See individual agents.

Dosage:

Children 6-11 years: Relief of respiratory symptoms: Oral:

Extendryl chewable tablet: One tablet every 4 hours; do not exceed 4 doses in 24 hours

Dallergy®: One-half caplet every 12 hours

Extendryl JR: One capsule every 12 hours

Extendryl syrup: 2.5-5 mL, may repeat up to every 4 hours depending on age and body weight

Children 12 years and Adults: Relief of respiratory symptoms: Oral: Note: If disturbances in urination occur in patients without renal impairment, medication should be discontinued for 1-2 days and should then be restarted at a lower dose

Dallergy®, Extendryl SR: One capsule every 12 hours

Extendryl: 1-2 chewable tablets every 4 hours

Extendryl syrup: 5-10 mL every 3-4 hours (4 times/day)

Elderly: Use with caution, may have increased adverse reactions

Dosage adjustment in renal impairment: Use is not recommended

Patient Education:

This medication may cause drowsiness, dizziness, dry mouth, blurred vision, and increased excitability or irritability (especially in children). You may not be alert. Avoid driving or doing other tasks or activities that until you see how this medicine affects you. Do not take other cold or cough preparations unless permitted to do so by prescriber. Avoid alcohol. Notify prescriber if decrease in urination, chest pain or pressure, palpitations, difficulty thinking clearly, eye pain, or a change in vision occur. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to become pregnant. Consult prescriber if breast-feeding.

Nursing Implications:

May cause increased excitability or irritability (especially in children); adverse effects are more likely in the elderly

Dental Health: Effects on Dental Treatment:

Key adverse event(s) related to dental treatment:

Chlorpheniramine: Significant xerostomia with prolonged use (normal salivary flow resumes upon discontinuation).

Methscopolamine: Anticholinergic side effects can cause a reduction of saliva production or secretion contributes to discomfort and dental disease (ie, caries, oral candidiasis and periodontal disease).

Phenylephrine: Tachycardia, palpitations, and xerostomia; use vasoconstrictor with caution.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions:

Use with caution since phenylephrine is a sympathomimetic amine which could interact with epinephrine to cause a pressor response

Mental Health: Effects on Mental Status:

Drowsiness is common; may cause excitability, nervousness, fatigue, or depression

Mental Health: Effects on Psychiatric Treatment:

Dry mouth and sedation may be exacerbated by concurrent psychotropic use

Dosage Forms:

[DSC] = Discontinued product

Caplet, extended release (Dallergy®): Chlorpheniramine maleate 12 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg

Capsule, extended release:

Extendryl JR: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg

Extendryl SR: Chlorpheniramine maleate 8 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg

Liquid (Chlor-Mes-D): Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 0.625 mg per 5 mL (480 mL)

Syrup:

Dallergy®: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 0.625 mg per 5 mL (480 mL)

Dehistine: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg per 5 mL (480 mL) [root beer flavor]

Extendryl: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg per 5 mL (480 mL) [contains sodium benzoate; root beer flavor]

Tablet:

Dallergy®: Chlorpheniramine maleate 4 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg [scored]

Vanex Forte™-D [DSC]: Chlorpheniramine maleate 8 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg [dye free; scored]

Tablet, chewable:

AH-Chew®: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg [grape flavor]

AH-Chew II: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 15 mg, and methscopolamine nitrate 1.25 mg [grape flavor]

Extendryl: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg [root beer flavor]

PCM: Chlorpheniramine maleate 2 mg, phenylephrine hydrochloride 10 mg, and methscopolamine nitrate 1.25 mg

Tablet, extended release: Chlorpheniramine maleate 8 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg

Drize®-R: Chlorpheniramine maleate 8 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg [dye free; scored]

Hista-Vent® DA: Chlorpheniramine maleate 8 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg [scored]

PCM Allergy: Chlorpheniramine maleate 12 mg, phenylephrine hydrochloride 20 mg, and methscopolamine nitrate 2.5 mg

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.