Uses

Indicated as an adjunct in the treatment of all forms of parkinsonism, including idiopathic, postencephalitic, and drug-induced parkinsonism. Helps control tremor, rigidity, and bradykinesia.

Do not use if

Contraindicated in glaucoma (especially narrow-angle), urinary retention, prostatic hypertrophy causing urinary obstruction, and hypersensitivity to the drug. Avoid in patients with tardive dyskinesia.

Side effects

Common anticholinergic side effects include dry mouth, blurred vision, urinary retention, constipation, and tachycardia. CNS effects include dizziness, confusion, hallucinations, and memory impairment, particularly in the elderly.

Warnings

Use with extreme caution in elderly patients due to high risk of confusion, falls, and urinary retention. Risk of hyperthermia in hot weather. May precipitate acute glaucoma. Abrupt discontinuation should be avoided.

How it works

Trihexyphenidyl is a centrally acting muscarinic (M1) receptor antagonist that reduces excess cholinergic activity in the striatum, thereby restoring the dopamine-acetylcholine balance disrupted in parkinsonism and producing beneficial effects on tremor and rigidity.

Storage

Store at room temperature (20–25°C), protected from light and moisture.