Some medicines and promethazine can affect each other and increase the chance of having side effects.
Cautions with other medicines Tell your pharmacist or doctor if you’re taking:
- a type of antidepressant called a monoamine oxidase inhibitor, such as phenelzine
- a type of painkiller called an opioid, such as codeine, morphine or oxycodone
- any medicine that makes you drowsy, gives you a dry mouth, or makes it difficult for you to pee – taking promethazine might make these side effects worse
If you’re taking a cough or cold remedy or a painkiller containing promethazine, check carefully what the other ingredients are.
For example, promethazine often comes mixed with paracetamol. If you take 2 medicines that both contain paracetamol, there’s a risk of overdose.
Ask your pharmacist for advice before you take this medicine together with any other painkillers or medicines.
Mixing promethazine with herbal remedies and supplements
There might be a problem taking some herbal remedies and supplements alongside promethazine, especially ones that cause side effects such as sleepiness, a dry mouth or making it difficult to pee.
Ask your pharmacist for advice.
Tell your doctor or pharmacist if you’re taking any other medicines, including herbal medicines, vitamins or supplements.
9. Common questions about promethazine
How does promethazine work?How is it different from other cough and cold remedies?How long does it take to work?How long can I take it for?Is promethazine addictive?How is promethazine different from other antihistamines?Can I take more than one antihistamine at a time?Will it help me sleep?Can I take it with painkillers?Can I drive or ride a bike with it?Will it affect my fertility?Will it affect my contraception?Can I drink alcohol with it?Is there any food or drink I need to avoid?Is it dangerous to take with recreational drugs?Can lifestyle changes help me sleep better?Can lifestyle changes help with hayfever and other allergies?
- HealthUnlocked: promethazine forum
- Allergy UK: charity
- Healthtalk: videos of real stories about sleep problems
- Itchy Sneezy Wheezy: website for parents