Piriton Tablets

Piriton is one of the UK's most well-known antihistamine tablets, containing 4mg of chlorphenamine maleate. It's used to quickly relieve a wide range of allergy symptoms, including hay fever, pet allergies, dust mite allergies, hives (nettle rash), skin rashes, food allergies, insect bites and stings, and even the itchy rash caused by chickenpox. It works by blocking histamine — the chemical your body releases during an allergic reaction — helping to ease itching, swelling, sneezing, and a runny nose. Unlike newer antihistamines, Piriton is a first-generation antihistamine, which means it acts fast but is more likely to cause drowsiness.

Piriton is fast-acting. It starts to relieve allergy symptoms within 15 to 30 minutes of taking it, making it a good option when you need quick relief from a sudden allergic reaction. Its effects typically last for 4 to 6 hours, which is why it needs to be taken more frequently throughout the day than once-daily antihistamines.

Adults and children aged 12 and over should take one tablet every 4 to 6 hours as needed, with no more than 6 tablets in any 24-hour period. Children aged 6 to 12 can take half a tablet every 4 to 6 hours, up to a maximum of 3 tablets (12mg) in 24 hours. Piriton is not recommended for children under 6 years old. If you are elderly or frail, a lower dose is advisable — speak to your GP or pharmacist before use. Do not use Piriton continuously for more than two weeks without consulting a doctor.

Yes — drowsiness is one of the most common side effects of Piriton, and it's something to be aware of before taking it. Unlike newer antihistamines such as cetirizine or loratadine, Piriton is a sedating antihistamine. This means it's more likely to make you feel tired or sleepy. You should avoid driving or operating heavy machinery while taking Piriton, and you must not drink alcohol alongside it as this will make the drowsiness significantly worse. Some people actually find the sedating effect helpful — for example, taking it in the evening to relieve night-time allergy symptoms.

As well as drowsiness, other side effects can include dry mouth, headache, dizziness, blurred vision, difficulty concentrating, and nausea. These tend to be more noticeable when you first start taking it and often ease as your body gets used to the medication. In rare cases, more serious side effects such as difficulty urinating or a severe allergic reaction can occur. If you experience anything unusual or concerning, stop taking Piriton and contact your doctor.

You should be cautious about taking Piriton alongside other medications. In particular, Piriton must not be taken if you have used monoamine oxidase inhibitors (MAOIs — a type of antidepressant) within the last 14 days, as this combination can be dangerous. You should also avoid taking it alongside other medicines that cause drowsiness, such as sleeping tablets or anxiety medication, as the sedative effects can be amplified. Always let your GP or our clinicians at Access Doctor know what other medications you are taking before starting Piriton.

Piriton is not recommended during pregnancy or breastfeeding unless your doctor has specifically advised it is necessary. There is limited data on its safety in pregnant women, and use in the third trimester in particular may cause reactions in newborn babies. Chlorphenamine may also be passed into breast milk. If you are pregnant, planning a pregnancy, or currently breastfeeding and need relief from allergy symptoms, please speak to your GP before taking Piriton.