Carbinoxamine Products | Cleanchem - Carbinoxamine is a first-generation antihistamine used to relieve symptoms of allergies, hay fever, and the common cold. It works by blocking H1 histamine receptors, thereby reducing sneezing, itching, watery eyes, and runny nose. Due to its sedative effects, it may also be used as a nighttime allergy remedy. Drowsiness and dry mouth are common side effects.