Trihexyphenidyl hydrochlorideProduct ingredient for Trihexyphenidyl

Trihexyphenidyl is a centrally acting muscarinic antagonist used for treatment of parkinsonism and drug-induced extrapyramidal disorders.^11,12 Its discovery was published in 1949 in a study looking for drugs with antispasmodic activity.⁹ Trihexyphenidyl is rarely used in the treatment of parkinsonism, and is not a first line treatment due to significant adverse effects.¹⁵ It has largely been replaced by drugs such as levodopa.¹⁵

Trihexyphenidyl was granted FDA approval on 13 May 1949.¹⁰