Chlorpheniramine Maleate
Class: First-generation antihistamine (H1 receptor antagonist)
Indications
- Allergic rhinitis
- Allergic conjunctivitis
- Urticaria & other allergic skin conditions
- Anaphylaxis (as adjunct to adrenaline)
- Hay fever
- Common cold (symptomatic relief)
Dosage
- Adults: 4 mg every 4–6 hours (max 24 mg/day)
- Children 6–12 years: 2 mg every 4–6 hours (max 12 mg/day)
- Children 2–6 years: 1 mg every 4–6 hours (max 6 mg/day)
- Children <2 years: Not recommended unless prescribed
Major Side Effects
- Drowsiness, sedation
- Dry mouth, blurred vision
- Constipation, urinary retention
- Dizziness, impaired coordination
- Rare: paradoxical excitation in children
Contraindications
- Hypersensitivity to chlorpheniramine
- Newborn or premature infants
- Narrow-angle glaucoma
- Severe hypertension or coronary artery disease
- Concurrent use with MAO inhibitors
Compatible Solvent / Form
- Oral tablets (2 mg, 4 mg)
- Oral syrup (1–2 mg/5 mL)
- Injectable form (rare use, adjunct in anaphylaxis)
Special Precautions
- Use caution in elderly (↑ risk of confusion, sedation, falls)
- May impair ability to drive or operate machinery
- Use with caution in asthma, COPD, prostatic hypertrophy
- Avoid alcohol or CNS depressants (enhances sedation)
Key Point: Chlorpheniramine is effective for allergy symptom relief but causes sedation; newer antihistamines are preferred for long-term use.