Promethazine
Also sold as: Phenergan
Prescription neededAllergy medicines (antihistamines)
Comes as:TabletSyrupInjection
Usual adult dose
Usual adult dose: 10 to 25 mg at night or up to 25 mg twice a day for allergy; 25 mg for nausea or travel sickness. Must not be given to children under 2 years.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- strong drowsiness
- dry mouth
- dizziness
- blurred vision
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- slowed breathing (especially in young children)
- fits
- uncontrolled muscle movements
- severe tissue damage if an injection leaks
Do not take it, or take care, if
- Children under 2 years (risk of fatal breathing problems)
- Glaucoma or difficulty passing urine
- Severe liver disease or epilepsy (use with caution)
- Do not drive or use machines; avoid alcohol
Interactions
Medicines that can react with this one.
Serious1 medicineDo not take these together unless your doctor says so.
- Morphine
Combined use can cause deep sedation and dangerously slowed breathing.