【藥品性質提示】 根據 2019 AGS Beers Criteria，本藥品為【潛在不適當用藥 (PIM)】，不建議用於老年人。

Parkinsonism, extrapyramidal disorders due to reserpine and phenothiazine, muscle rigidity.

Trihexyphenidyl is an antimuscarinic antiparkinsonian agent. It produces an atropine-like blocking action on parasympathetic-innervated peripheral structures, including smooth muscle.

Trihexyphenidyl is rapidly absorbed from the GI tract. Following oral administration of trihexyphenidyl hydrochloride tablets, the onset of action occurs within 1 hour, peak effects last 2–3 hours, and the duration of action is 6–12 hours. The metabolic fate of trihexyphenidyl has not been determined; the drug is excreted in the urine, probably as unchanged drug.

Closed angle galucoma, paralytic ileus or pyloric stenosis, prostatic enlargement.

C

It is unknown whether trihexyphenidyl is excreted in human breast milk. Infants may be very sensitive to the effects of antimuscarinic medications. Trihexyphenidyl should not be used during breast-feeding.

Dry mouth, fatigue, vertigo, gastric upset, and psychotic disturbance.

Usual dose 2 mg TID or QID. Maximum dose: 15 mg/day