Diphenhydramine
Also sold as: Benadryl
No prescription neededAllergy medicines (antihistamines)
Comes as:TabletCapsuleSyrupInjection
Also sold as: Benadryl
Usual adult dose: 25 to 50 mg every 4 to 6 hours when needed. Do not take more than 300 mg in 24 hours. Not for children under 6 years unless a doctor advises.
Your doctor may give you a different dose. Children's doses depend on weight.
Stop taking it and see a doctor straight away if you notice:
Medicines that can react with this one.
Both have anticholinergic effects; more dry mouth, constipation, confusion and urine retention.
Together they cause more drowsiness and slowed reactions.
Combined use increases drowsiness and the risk of slowed breathing.