Chloropheniramine Cas number: 132-22-9 Molecular Formula：C₁₆H₁₉ClN₂

Chlorpheniramine is a drug in the class of first-generation antihistamines, used to help alleviate symptoms of allergic reactions potentiated by histamine release. Though it is included in many multisymptom over-the-counter cold relief medications, the Food and Drug Administration (FDA) issued a safety alert in March 2011 detailing some risks associated with these medications. The safety alert also indicated that increased enforcement of FDA laws governing the marketing of these drugs would occur, as many of the products had not been approved in their current formulations for safety, effectiveness, and quality.
Chlorpheniramine is commonly used in small-animal veterinary medicine for its antihistaminic/antipruritic effects, especially for the treatment of pruritus in cats, and occasionally as a mild sedative.