Trihexyphenidyl (Trihexyphenidyl Hydrochloride) - Description and Clinical Pharmacology

DESCRIPTION

Trihexyphenidyl hydrochloride is a synthetic antispasmodic drug available in the following forms: Tablets, 2 mg and 5 mg. It is designated chemically 1-Piperidinepro- panol,α-cyclohexyl-α-phenyl-, hydrochloride. The structural formula is represented below:

C₂₀H₃₁NO·HCl            M.W. 337.93

Trihexyphenidyl Hydrochloride Tablets USP 2 mg and 5 mg contain the following inactive ingredients: colloidal silicon dioxide, dibasic calcium phosphate, lactose monohydrate, magnesium stearate, microcrystalline cellulose and sodium starch glycolate.

CLINICAL PHARMACOLOGY

Trihexyphenidyl HCl is the substituted piperidine salt, 3-(1-piperidyl)-1-phenyl-cyclohexyl-1-propanol hydrochloride, which exerts a direct inhibitory effect upon the parasympathetic nervous system. It also has a relaxing effect on smooth musculature; exerted both directly upon the muscle tissue itself and indirectly through an inhibitory effect upon the parasympathetic nervous system. Its therapeutic properties are similar to those of atropine, although undesirable side effects are ordinarily less frequent and severe than with the latter.