If you or your child has been prescribed chlorphenamine, follow your doctor's instructions about how and when to take it.
If you've bought chlorphenamine or any medicine containing chlorphenamine from a pharmacy, follow the instructions that come with the packet, or ask your pharmacist for advice.
If you or your child's symptoms do not get better within a few days, talk to a doctor.
Dosage and how to take chlorphenamine
Dosage and strength
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.
How long to take it for
Only take chlorphenamine when you need to.
For allergies, you may only need to take chlorphenamine on the days you feel you need to. For example, coming into contact with something like animal hair may have triggered your symptoms.
If you have a reaction to an insect bite or a medicine, you may only need to take chlorphenamine for a day or 2.
For hay fever, you may need to take it regularly to prevent symptoms during spring and summer.
Do not take chlorphenamine for longer than 2 weeks without speaking to a doctor. Speak to your doctor if your symptoms are not improving.
If you're taking it for a cough or cold and your symptoms last for more than 2 weeks, speak to your doctor. Do not take it for longer than that without checking with your doctor.
Talk to your doctor or pharmacist if you're unsure how long you need to take chlorphenamine for.
If you forget to take it
If you miss a dose of chlorphenamine, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take your next dose at the usual time.
Do not take 2 doses at the same time, or take an extra dose to make up for a forgotten one.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
If you take too much
Taking too much chlorphenamine can be dangerous. It's important to get medical advice if you take more than the recommended dose.
Immediate action required: Call 999 or go to A&E now if:
You or your child take more than the recommended dose of chlorphenamine and:
- have a very fast, irregular or pounding heartbeat
- have breathing problems
- have a seizure or fit
- become unconscious
- have uncontrolled movements, especially in the hands or feet
- feel confused or agitated, or have difficulty speaking
- see or hear things that are not there (hallucinations)
Urgent advice: Contact 111 for advice now if:
- you take more than the recommended dose of chlorphenamine, even if you do not have any symptoms
Get help from 111 online or call 111.
Call 111 if you're asking about a child under the age of 5 years.
If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the chlorphenamine packet or leaflet inside it, any remaining medicine, and any other medicines you take.