About chlorpheniramine maleate
First-generation antihistamine
Used for
- Severe allergic reactions, including as an add-on in anaphylaxis
- Acute allergic conditions when oral treatment is unsuitable
Usual adult dose
Usually 10–20 mg by slow intravenous injection, intramuscular injection, or subcutaneous injection; maximum 40 mg in 24 hours.
Usual dose in children
Children 1 month–1 year: 250 micrograms/kg; 1–5 years: 2.5–5 mg; 6–12 years: 5–10 mg, by injection. Repeat only as directed; maximum 2 doses daily.
Common side effects
- Drowsiness and dizziness
- Dry mouth, blurred vision, or constipation
- Low blood pressure, especially after rapid injection
- Difficulty passing urine
Important warnings
- Not a substitute for adrenaline in anaphylaxis
- May cause marked drowsiness; avoid alcohol and driving
- Use cautiously with glaucoma, urinary retention, or older age
- Rapid intravenous administration can cause low blood pressure
Pregnancy
Use only when clinically needed; pregnancy safety information is limited. Prescribed treatment should weigh benefits against risks.
Breastfeeding
May cause infant drowsiness or irritability and may reduce milk supply, particularly with repeated doses.
Interactions
- Alcohol, opioids, sedatives, and sleeping medicines increase drowsiness
- Monoamine oxidase inhibitors can intensify anticholinergic effects
- Other anticholinergic medicines can worsen dry mouth, constipation, or urinary retention
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.