Benzatropine

Anticholinergic·Psychiatry - Acute Calming & Sedation

Drug-induced extrapyramidal symptoms (EPS) excluding tardive dyskinesia

PBSANTICHOLINERGICCogentin, Benztrop2 mg tabletS4+1

Max Dose

6 mg/day

Half-life

12-24 h

Dystonia

RESCUE DRUG

Delirium

HIGH RISK

Rapid Summary

Overview

Potent central anticholinergic. The definitive antidote for acute dystonic reactions and severe Parkinsonism caused by First-Generation Antipsychotics.

Maximum Dose

Max 6 mg/day (Doses > 4mg/day strongly risk toxic psychosis).

Clinical Focus

Highly toxic to the elderly. Causes frank anticholinergic delirium, profound urinary retention, and severe constipation.

Bottom Line

Benzatropine is an anticholinergic for acute drug-induced dystonia and parkinsonism, but causes significant anticholinergic toxicity and should not be used for tardive dyskinesia.

Formulation & Access

Brand Names

Cogentin, Benztrop

Oral Routes

Tablets (2 mg).

Parenteral

Ampoules (2 mg/2 mL) for IM or IV use.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Drug-induced extrapyramidal symptoms (EPS) excluding tardive dyskinesia. Adjunct in Parkinson's disease.

Clinical Place

Emergency rescue drug stored on every psychiatric and ED ward for antipsychotic reactions.

Quick reference

Class & Role

Anticholinergic — Potent central anticholinergic.

Route / Formulation

Tablets (2 mg). (Cogentin, Benztrop)

Usual Dose & Max

IM or IV 1-2 mg STAT. Repeat after 15 mins if no response. Follow with oral therapy for 3-5 days to prevent relapse. Max 6 mg/day (Doses > 4mg/day strongly risk toxic psychosis).

Key Indication Doses

Acute Dystonic Reaction (Oculogyric Crisis/Torticollis): IM or IV 1-2 mg STAT. Repeat after 15 mins if no response. Follow with oral therapy for 3-5 days to prevent relapse. Antipsychotic-Induced Parkinsonism: PO 1-2 mg OD to BD.

Best Uses

Benzatropine is an anticholinergic for acute drug-induced dystonia and parkinsonism, but causes significant anticholinergic toxicity and should not be used for tardive dyskinesia.

Avoid / Cautions

Untreated narrow-angle glaucoma, mechanical bowel obstruction, severe BPH, tardive dyskinesia (worsens it).

Key Risks

Neurological: Toxic psychosis, hallucinations, delirium, memory loss (especially in older adults). Gastrointestinal: Severe dry mouth, paralytic ileus, constipation. Ocular: Blurred vision, precipitation of narrow-angle glaucoma. Genitourinary: Urinary retention.

Key Interactions

Additive anticholinergic toxidrome with TCAs (Amitriptyline), antihistamines (Promethazine), and Clozapine (risk of toxic megacolon).

Monitoring

Monitor bowel and bladder output. A young male on Haloperidol + Benzatropine is at extreme risk of sudden urinary retention requiring a catheter.

Clinical Pearl

A dystonic reaction (neck spasming backward, jaw locked, eyes rolled up) is terrifying for the patient. Pushing 1-2mg of IV Benzatropine is one of the most rewarding moments in medicine; the spasm literally melts away within 60 seconds.

Access

Cogentin, Benztrop2 mg tablet

Brand: Cogentin, Benztrop
Formulation: Tablets (2 mg)

Benzatropine

Anticholinergic·Psychiatry - Acute Calming & Sedation

Drug-induced extrapyramidal symptoms (EPS) excluding tardive dyskinesia

PBSANTICHOLINERGICCogentin, Benztrop2 mg tabletS4+1

Max Dose

6 mg/day

Half-life

12-24 h

Dystonia

RESCUE DRUG

Delirium

HIGH RISK

Rapid Summary

Overview

Potent central anticholinergic. The definitive antidote for acute dystonic reactions and severe Parkinsonism caused by First-Generation Antipsychotics.

Maximum Dose

Max 6 mg/day (Doses > 4mg/day strongly risk toxic psychosis).

Clinical Focus

Highly toxic to the elderly. Causes frank anticholinergic delirium, profound urinary retention, and severe constipation.

Bottom Line

Benzatropine is an anticholinergic for acute drug-induced dystonia and parkinsonism, but causes significant anticholinergic toxicity and should not be used for tardive dyskinesia.

Formulation & Access

Brand Names

Cogentin, Benztrop

Oral Routes

Tablets (2 mg).

Parenteral

Ampoules (2 mg/2 mL) for IM or IV use.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Drug-induced extrapyramidal symptoms (EPS) excluding tardive dyskinesia. Adjunct in Parkinson's disease.

Clinical Place

Emergency rescue drug stored on every psychiatric and ED ward for antipsychotic reactions.

Quick reference

Class & Role

Anticholinergic — Potent central anticholinergic.

Route / Formulation

Tablets (2 mg). (Cogentin, Benztrop)

Usual Dose & Max

IM or IV 1-2 mg STAT. Repeat after 15 mins if no response. Follow with oral therapy for 3-5 days to prevent relapse. Max 6 mg/day (Doses > 4mg/day strongly risk toxic psychosis).

Key Indication Doses

Best Uses

Benzatropine is an anticholinergic for acute drug-induced dystonia and parkinsonism, but causes significant anticholinergic toxicity and should not be used for tardive dyskinesia.

Avoid / Cautions

Untreated narrow-angle glaucoma, mechanical bowel obstruction, severe BPH, tardive dyskinesia (worsens it).

Key Risks

Key Interactions

Additive anticholinergic toxidrome with TCAs (Amitriptyline), antihistamines (Promethazine), and Clozapine (risk of toxic megacolon).

Monitoring

Monitor bowel and bladder output. A young male on Haloperidol + Benzatropine is at extreme risk of sudden urinary retention requiring a catheter.

Clinical Pearl

Access

Cogentin, Benztrop2 mg tablet

Brand: Cogentin, Benztrop
Formulation: Tablets (2 mg)