Promethazine (Phenergan)

Promethazine is not suitable for some people. For example, check with your doctor if you have problems peeing or have epilepsy.

Promethazine comes as tablets and liquid. Follow the instructions that come with your medicine.

Side effects of promethazine include feeling tired, feeling dizzy, or headaches. More serious side effects can happen in rare cases.

It can cause problems to take promethazine with other medicines, such as medicines that cause drowsiness, a dry mouth or difficulty peeing.

Most adults can take promethazine.

Children aged 2 to 5 years may be able to take promethazine liquid if it has been prescribed for them. Children aged 6 years or over can take promethazine liquid without a prescription.

Most children aged 5 years or over can take promethazine tablets for allergies or sickness.

Some types of promethazine are only suitable for older children.

Some promethazine products for cold symptoms can be taken from the age of 12 years and some can only be taken from the age of 16 years.

Your doctor or pharmacist will advise which are the safest types for your child.

Do not give children aged 5 years or under cough and cold medicines containing promethazine.

Promethazine is not suitable for some people. To make sure it's safe for you, tell your doctor or pharmacist if you:

• have ever had an allergic reaction to promethazine or any other medicine
• have an eye problem called primary angle closure glaucoma
• have problems peeing or emptying your bladder
• have epilepsy or any other health problem that causes seizures or fits
• have breathing difficulties, such as asthma
• have an enlarged prostate
• have heart problems
• have liver or kidney problems
• are due to have an allergy test, as taking promethazine can affect your results, so you may need to stop taking it a few days before your test – ask the clinic where you are due to have your allergy test
• are unable to have any alcohol – some liquid promethazine products contain a very small amount of alcohol, so check the ingredients and the packaging carefully
• are trying to get pregnant, as taking promethazine can affect home pregnancy tests – if you think you're pregnant, speak to your doctor so they can arrange a blood test instead

Promethazine tablets come in strengths of 10mg, 20mg or 25mg.

The liquid contains 5mg of promethazine in 5ml.

If you're taking liquid promethazine, follow the instructions that come with the medicine for how much to take.

For adults and children aged 10 years or older, your dose depends on why you're taking it.

For hay fever or hives the dose can vary from 10mg twice a day to 20mg 3 times a day or 25mg once or twice a day.

For preventing motion sickness you'll usually take 25mg the night before your journey. Some products only need to be taken 1 to 2 hours before travelling, if it's a short journey.

For treating motion sickness take 25mg as soon as possible and 25mg the same evening. You can then take 25mg the following evening, if you need it.

For vertigo the dose can vary from 25mg a day to 25mg 4 times a day.

Doses are lower for children aged 9 years or under. To find out what dose to give your child, ask your doctor or pharmacist for advice or check the medicine packet.

Dosage for promethazine mixed with other medicines

Promethazine can come mixed with other medicines, such as paracetamol. This is usually used to treat cough and cold symptoms. Your dose will depend on the type of medicine you're taking.

Check the instructions on the packaging for how much to take. Ask your pharmacist or doctor if you're unsure.

How to take it

You can take promethazine with or without food.

How to take tablets

Always take your promethazine tablets with a drink of water. Swallow them whole. Do not chew them.

How to take liquid

Liquid medicines containing promethazine come with a plastic syringe or spoon to help you measure out the right dose.

If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

There are things you can do to help cope with these side effects of promethazine:

Drowsiness usually wears off within 12 hours of taking a dose. Do not drive, cycle or use tools or machinery if you're feeling this way.

Speak to your pharmacist or doctor if nightmares do not go away or are troubling you.

Stop what you're doing and sit or lie down until you feel better. If the feeling does not go away or is troubling you, do not take any more promethazine and speak to a pharmacist or doctor.

Make sure you rest and drink plenty of fluids. Ask your pharmacist to recommend a painkiller. Talk to your doctor if the headaches last longer than a week or are severe.

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Promethazine can be taken in pregnancy. There is no evidence that it is harmful to your baby, but it can have side effects such as drowsiness (feeling sleepy).

For the treatment of hay fever your doctor or pharmacist may recommend a non-drowsy antihistamine (loratadine).

If your baby is healthy, you can take promethazine while breastfeeding. However, it's best to only take it occasionally or for a short time. Talk to your doctor or pharmacist first as other medicines might be better.

It's not known how much promethazine passes into breast milk but it's only likely to be low levels, and your baby will not be able to absorb a lot into their body. For many years, it has been used while breastfeeding without causing side effects in breastfed babies.

However, promethazine is a drowsy antihistamine and may also make your baby sleepy.

Medicines containing promethazine that you buy from a pharmacy may also contain other ingredients. Check with a pharmacist or doctor first if you're breastfeeding.

It's very rare for breastfed babies to have side effects from medicines you're taking. But it's important to keep monitoring your baby if you're taking any medicine while breastfeeding.

Contact your healthcare professional or call 111 as soon as possible if you notice that your baby is:

• unusually sleepy
• not feeding as well or putting on weight as you would expect
• being irritable

If your baby has any symptoms that are not listed, or if you're worried about them, you can also call 111 or contact any healthcare professional.

Keep breastfeeding as usual until you've got advice about your baby's symptoms.

It's important not to share a bed with your baby while you're taking promethazine.

Some medicines and promethazine can affect each other and increase the chance of having side effects.

Check with a pharmacist or your doctor if you're taking any other medicines, including:

• any antidepressants, including monoamine oxidase inhibitors such as phenelzine, or other medicines for mental health conditions
• medicines used to treat an irregular heartbeat (arrhythmia), such as amiodarone
• medicines to treat epilepsy or seizures
• antibiotics to treat an infection, such as erythromycin
• 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.

These are not all the medicines that may cause problems if you take them with promethazine. For a full list, see the leaflet inside your medicine packet.

Taking promethazine with painkillers

It's safe to take promethazine with some painkillers, such as paracetamol or ibuprofen.

However, it's important to check the ingredients of your medicine carefully. This is because promethazine often comes mixed with a painkiller such as paracetamol.

If you take 2 medicines that both contain paracetamol, there's a risk of overdose. Speak to your pharmacist if you're not sure whether a medicine already contains a painkiller.

If you take promethazine with painkillers that contain codeine (such as co-codamol or other prescription painkillers), you may feel very tired and sleepy.

Do not drive, ride a bike or operate machinery or tools if this happens to you.