Piriton Syrup 150ml Piriton Syrup 150ml Piriton Syrup 150ml is an antihistamine syrup containing chlorphenamine maleate to help relieve allergy symptoms such as hay fever, pet allergies, skin allergies, insect bites, hives, and itching associated with chickenpox. It is suitable for adults and children aged 1 year and over. This syrup comes in a 150ml bottle and is supplied with a measuring spoon for easy dosing.