trihexyphenidyl

Adjunctive therapy • Brands: Artane

Last reviewed: 2025-12-30

General information

Primary label indications include: Parkinsonism (label).
Class: Adjunctive therapy
Common US brands: Artane
Typical dose range: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-30

Dosing & forms

Forms/strengths: Tablets: 2 mg and 5 mg (label).
Frequency: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).
Typical range: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).

Mechanism (brief)

Anticholinergic (antimuscarinic) antiparkinson agent used for parkinsonism and to manage extrapyramidal reactions to antipsychotics. It can improve drug-induced parkinsonism and acute dystonia, but does not treat tardive dyskinesia and may worsen it; anticholinergic adverse effects often limit use.

Metabolism & Half‑life

Metabolism: Hepatic metabolism (extent not well characterized in current labeling) (label/clinical).
Half‑life: —

Therapeutic Drug Monitoring (TDM)

Recommended: No

View labelExact

Monitoring highlights

Anticholinergic adverse-effect monitoring (bowel function, urinary retention, blurry vision, dry mouth, tachycardia) (label/clinical).
Mental status monitoring (confusion/delirium), especially in older adults or when anticholinergic burden is high (clinical).
Screen for glaucoma risk and urinary obstruction symptoms when relevant (label/clinical).

Sources

Trihexyphenidyl hydrochloride tablets prescribing information — DailyMed (2023)
Recognition and Management of Antipsychotic-Induced Parkinsonism in Older Adults A Narrative Review — Medicines (2021)
Managing Antipsychotic-Induced Acute and Tardive Dystonia — Drug Safety (1998)
Anticholinergic Burden and Cognitive Performance in Patients With Schizophrenia A Systematic Literature Review — Frontiers in Psychiatry (2021)
AGNP Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology — Pharmacopsychiatry (2018)

General information

Primary label indications include: Parkinsonism (label).

Class: Adjunctive therapy

Common US brands: Artane

Typical dose range: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).

Therapeutic drug monitoring not routinely recommended.

Last reviewed: 2025-12-30

Dosing & forms

Forms/strengths: Tablets: 2 mg and 5 mg (label).

Frequency: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).

Typical range: Parkinsonism: labeling describes starting at 1 mg on day 1, then increasing by 2 mg increments at intervals of 3–5 days toward a typical daily total of 6–10 mg/day (label).

Monitoring highlights

Anticholinergic adverse-effect monitoring (bowel function, urinary retention, blurry vision, dry mouth, tachycardia) (label/clinical).

Mental status monitoring (confusion/delirium), especially in older adults or when anticholinergic burden is high (clinical).

Screen for glaucoma risk and urinary obstruction symptoms when relevant (label/clinical).