Triprolidine
Triprolidine is an over-the-counter antihistamine with anticholinergic properties. It is used to combat the symptoms associated with allergies and is sometimes combined with other cold medications designed to provide general relief for flu-like symptoms. As with many antihistamines, the most common side effect is drowsiness.
Triprolidine was patented in 1948 and came into medical use in 1953, and has mostly been replaced in popular medications by other antihistamines including diphenhydramine, promethazine, chlorpheniramine, as well as by second-generation antihistamines including loratadine and fexofenadine. Triprolidine remains an ingredient in the cold medicine Actifed in many territories.