Chlorphenamine
Also sold as: Piriton
No prescription neededAllergy medicines (antihistamines)
Comes as:TabletSyrupInjection
Usual adult dose
Usual adult dose: 4 mg every 4 to 6 hours when needed. Do not take more than 24 mg in 24 hours. Children: dose by age or weight — ask your doctor or pharmacist; not for children under 1 year.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- drowsiness
- dry mouth
- blurred vision
- dizziness
- constipation
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- severe allergic reaction
- fits
- fast or irregular heartbeat
- inability to pass urine
Do not take it, or take care, if
- Glaucoma (raised eye pressure)
- Enlarged prostate or difficulty passing urine
- Epilepsy (use with caution)
- Do not drive or use machines if drowsy; avoid alcohol
- Elderly people (more confusion and falls — use with caution)
Interactions
Medicines that can react with this one.
Moderate2 medicinesTake together only with care. Ask your doctor or pharmacist.
Minor1 medicineUsually not a problem, but tell your doctor.
- Betahistine
Antihistamines may reduce the effect of betahistine.