Wiktionary
trihexyphenidyl
n. An antiparkinsonian drug of the antimuscarinic class.
Wikipedia
Trihexyphenidyl
Trihexyphenidyl (Artane, Apo-Trihex, Parkin, Pacitane), also known as benzhexol and trihex, is an antiparkinsonian agent of the antimuscarinic class. It has been in clinical usage for decades.