Cogentin (Benztropine) Medication Class
Cogentin (benztropine mesylate) is an anticholinergic medication primarily used to treat extrapyramidal side effects caused by antipsychotic medications and as an adjunct therapy for Parkinson's disease. 1
Pharmacology and Mechanism of Action
Benztropine possesses both anticholinergic and antihistaminic properties, though its therapeutic effects in managing movement disorders are primarily attributed to its anticholinergic activity. According to the FDA label, its anticholinergic activity is approximately equal to atropine when tested in isolated guinea pig ileum, but only about half as potent when administered orally to unanesthetized cats 1.
Primary Clinical Indications
Treatment of extrapyramidal side effects (EPS) caused by neuroleptic/antipsychotic medications, including:
- Acute dystonia (involuntary muscle spasms)
- Drug-induced parkinsonism (bradykinesia, tremor, rigidity)
- Akathisia (motor restlessness) 2
Adjunctive treatment in all forms of parkinsonism 1
Not indicated for tardive dyskinesia - The FDA label specifically notes that benztropine is not effective for tardive dyskinesia 1
Dosing Considerations
- Typical dosage range: 1-2 mg daily
- Maximum daily dose: 6 mg 2
- Administration: Usually given orally, can be divided throughout the day
Side Effects and Precautions
Benztropine can cause significant anticholinergic side effects, including:
- Central nervous system effects: confusion, memory impairment, hallucinations, delirium 3
- Peripheral anticholinergic effects: dry mouth, blurred vision, urinary retention, constipation 2
- Risk of stereotypy (repetitive motor automatisms) 3
- Potential for abuse and dependence
- Withdrawal-emergent dyskinesia has been reported when discontinuing benztropine 4
Special Considerations
- Elderly patients should receive lower doses due to increased sensitivity to anticholinergic effects 2
- Caution in patients with cardiovascular disease, glaucoma, prostatic hypertrophy
- Contraindicated in patients with angle-closure glaucoma
Clinical Pearls
- When used for EPS management, benztropine is particularly effective for acute dystonia, which typically responds rapidly to anticholinergic treatment 2
- For drug-induced parkinsonism, benztropine can be added to the regimen or the antipsychotic dose can be reduced 2
- Benztropine is less effective for akathisia compared to beta-blockers or benzodiazepines 2
- Fatal toxicity, while rare, has been reported with benztropine overdose 5
By understanding benztropine's classification as an anticholinergic agent and its specific indications for movement disorders, clinicians can appropriately utilize this medication while being mindful of its potential adverse effects.