Chlorphenamine belongs to a group of medicines known as sedating antihistamines. It is used to relieve allergies (such as hay fever, food and drug allergies, and allergic skin reactions), and to relieve itching caused by infections such as chickenpox. It is also given to treat a type of allergic reaction called anaphylaxis, which is a medical emergency.
This is a companion discussion topic for the original article at https://patient.info/medicine/chlorphenamine-for-allergies-allerief-hayleve-piriton