Klorfeniramin is an antihistamine used to relieve allergy symptoms, fever, and the common cold. These symptoms include rashes, watery eyes, itchy eyes/nose/throat/skin, cough, runny nose, and sneezing.These drugs work by blocking certain natural substances (histamine) that your body makes during an allergic reaction. By blocking other natural materials made by your body (acetylcholine), helping dry out some bodily fluids to relieve symptoms of sepe