3. Chlorphenamine

Chlorphenamine

  • Chlorphenamine is used to help prevent allergic conditions.
  • The most common side-effect is drowsiness.
  • Chlorphenamine may affect your ability to drive and use machines. Do not drive if you are not fully alert or able to see clearly.
Type of medicine Antihistamine
Used for Allergic conditions
Also called Allercalm® allergy relief
Allerief®
Hayleve®
Piriton®
Available as Tablets, oral solution and injection

Chlorphenamine is used to prevent and relieve allergic conditions such as hay fever and some allergic skin reactions. It is also used in the emergency treatment of some allergic reactions.

Exposure to substances such as pollen, pet fur, house dust, or insect bites can cause the body to produce a chemical called histamine. The release of histamine causes allergic symptoms which can include itchy rashes, sneezing, watery eyes, and a runny or blocked nose.

Chlorphenamine stops the effects of histamine and helps to relieve these symptoms.

Before taking chlorphenamine make sure your doctor, dentist or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have glaucoma.
  • If you have prostate problems, or have been experiencing difficulty passing urine.
  • If you know you have a blockage in your small intestines.
  • If you have liver problems.
  • If you have epilepsy.
  • If you are taking other medicines, including those available to buy without a prescription, herbal and complementary medicines.
  • If you have ever had an allergic reaction to an antihistamine or to any other medicine.
  • Before starting this treatment, read the manufacturer's printed information leaflet from inside the pack.
  • Take chlorphenamine exactly as your doctor advises you. You will be told how many doses to take each day.
  • It is not important whether you take your doses before or after food.
  • If you forget to take a dose, do not worry, take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.
  • Chlorphenamine may make you sleepy. If this happens, do not drive or use tools or machines, and do not drink alcohol.
  • If you buy any medicines, check with a pharmacist that they are safe to take alongside chlorphenamine.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking an antihistamine.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common side-effects - these affect less than 1 in 10 people who take this medicine What can I do if I experience this
Drowsiness, blurred vision or dizziness Make sure your reactions are normal before driving, operating machinery or doing any other jobs which could be dangerous if you were not fully alert or able to see properly
Headache Ask your pharmacist to recommend a suitable painkiller. If the headache continues, speak with your doctor
Difficulty passing urine Speak with your doctor if this becomes troublesome
Dry mouth Try chewing sugar-free gum or sweets
Stomach upset Stick to simple foods - avoid rich or spicy foods

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

  • Never take more than the prescribed dose. If you suspect that you or someone else has taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
  • This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
  • Never keep out of date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
  • If you have any questions about this medicine ask your pharmacist.
Provide feedback

Further reading & references

  • British National Formulary; 62nd Edition (Sep 2011) British Medical Association and Royal Pharmaceutical Society of Great Britain, London
  • Manufacturer's PIL, ALLERcalm® Allergy Relief Tablets 4mg; Manufacturer's PIL, ALLERcalm® Allergy Relief Tablets 4mg, Actavis UK Ltd, electronic Medicines Compendium. Dated November 2008.
Original Author: Helen Allen Current Version:
Last Checked: 07/06/2011 Document ID: 3207  Version: 22 © EMIS

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

The Information Standard - certified member

The authors and editors of this article create up to date content reflecting reliable research evidence, guidance and best clinical practice. Learn more

Advertisements