Chlorphenamine (Piriton)

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

Chlorphenamine comes as tablets and a liquid that you usually take 3 to 6 times a day. Follow the instructions that come with your medicine.

Side effects of chlorphenamine include feeling sleepy, sick or dizzy. More serious side effects can happen in rare cases.

Chlorphenamine can be taken during pregnancy, but other antihistamines may be preferred. Always check with a pharmacist or doctor.

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

Most adults and children aged 1 year old and over can take chlorphenamine.

Do not give children under 6 years old cough or cold medicines that contain chlorphenamine along with other ingredients.

Chlorphenamine 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 chlorphenamine or any other medicine
• have an eye problem called primary angle closure glaucoma
• have taken a type of antidepressant called monoamine oxidase inhibitors in the last 14 days
• have problems peeing or emptying your bladder
• have epilepsy or another health problem that can cause fits or seizures
• have breathing difficulties such as asthma or a lung condition
• have heart disease or very high blood pressure
• have an enlarged prostate
• have liver or kidney problems
• are due to have an allergy test, as taking chlorphenamine may affect the results, so you might need to stop taking it a few days before the test – ask a pharmacist or your doctor for advice
• are unable to have any alcohol – some liquid chlorphenamine products contain a very small amount of alcohol, so check the ingredients and the packaging carefully
• are a frail, older adult – you may have more side effects, such as confusion

Chlorphenamine comes as 4mg tablets or a liquid that contains 2mg in 5ml.

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

The usual dose for adults and children aged 12 years old or over is 1 tablet every 4 to 6 hours. Do not take more than 6 tablets in 24 hours.

Doses are lower for children under 12 years old, and they may take it less often than adults. Follow the instructions in the box for how much to give, or follow the instructions from their doctor if they've been prescribed chlorphenamine.

Babies under 1 year old should only take chlorphenamine that's been prescribed by a doctor. Do not give children under 6 years old cough or cold medicines that contain chlorphenamine.

The usual dose for older adults who are frail is 1 tablet every 6 to 8 hours. Do not take more than 3 tablets in 24 hours. Speak to your doctor or pharmacist before taking it as you're more likely to get side effects.

When used for coughs and colds, chlorphenamine is mixed with other medicines in a liquid that you swallow. Follow the instructions on the bottle or packaging for how much to take.

How to take it

You can take chlorphenamine with or without food.

Swallow chlorphenamine tablets with a drink of water, milk or juice. The 4mg tablets can be broken in half for children and people taking lower doses.

Chlorphenamine liquid may be easier for children to take than tablets. The medicine will 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 because it will not measure the right amount.

These common side effects of chlorphenamine happen in more than 1 in 100 people. There are things you can do to help cope with them:

Drowsiness usually wears off 4 to 6 hours after a dose. Do not drive, ride a bike or use tools or machinery if you're feeling this way.

Try taking your tablets with food. It may also help if you do not eat rich or spicy food while you're taking chlorphenamine.

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 chlorphenamine and speak to a pharmacist or your doctor.

Do not drive or ride a bike if you're feeling dizzy or unable to concentrate.

Chew sugar-free gum or suck sugar-free sweets.

Make sure you rest and drink plenty of fluids. Ask your pharmacist to recommend a painkiller.

Talk to your doctor if the headaches do not go away or are severe.

Do not drive, ride a bike or use tools or machinery while this is happening.

This is usually only a mild problem but if it bothers you, speak to your pharmacist or doctor as you may need to change your treatment.

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.

Chlorphenamine can be taken in pregnancy. There is no good evidence that it is harmful to your baby, but it can cause side effects such as feeling drowsy.

Your doctor or pharmacist may recommend a non-drowsy antihistamine (such as loratadine) rather than chlorphenamine.

If your baby is healthy, you can take chlorphenamine while breastfeeding, but a non-drowsy antihistamine might be better. Talk to your doctor or pharmacist first, and they'll help you to decide.

It's not known how much chlorphenamine gets into breast milk, but it's only likely to be low levels. For many years, it has been widely used while breastfeeding, without causing side effects in babies. However it's better to only take it occasionally, or for a short time, as it could make them sleepy.

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 your baby:

• is not feeding as well as usual
• seems unusually sleepy
• seems unusually 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 chlorphenamine.

Some medicines and chlorphenamine can affect each other and increase the chances of you having side effects.

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

• a type of antidepressant called a monoamine oxidase inhibitor, such as phenelzine
• phenytoin (an anti-epilepsy medicine)
• any medicines for anxiety or to help you sleep
• any medicine that makes you drowsy, gives you a dry mouth, or makes it difficult for you to pee – taking chlorphenamine might make these side effects worse

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

Taking chlorphenamine with painkillers

It's safe to take chlorphenamine with painkillers like paracetamol or ibuprofen that you buy from a pharmacy or shop.

But if you take chlorphenamine with painkillers that contain codeine (such as co-codamol) or other prescription painkillers, you're more likely to have side effects.