Benztropine Oral Dosing
For drug-induced extrapyramidal disorders (dystonic reactions), the recommended oral dose of benztropine is 1-2 mg daily or twice daily, with an initial treatment dose of 1-2 mg that can be repeated as needed. 1, 2
Dosing by Indication
Acute Dystonic Reactions from Neuroleptics
- Initial dose: 1-2 mg IV or IM for one dose 1
- Maintenance: 1-2 mg orally daily or twice daily if needed 1
- For drug-induced extrapyramidal disorders, the FDA-approved dosing is 1-4 mg once or twice daily orally, with dosage individualized to patient need 2
Parkinsonism (Idiopathic and Postencephalitic)
- Usual daily dose: 1-2 mg orally, with a range of 0.5-6 mg 2
- For idiopathic parkinsonism, initiate with 0.5-1 mg at bedtime; some patients require 4-6 mg daily 2
- For postencephalitic parkinsonism, initiate with 2 mg daily in one or more doses; highly sensitive patients may start with 0.5 mg at bedtime 2
Dosing Principles and Titration
Therapy should be initiated with a low dose and increased gradually at 5-6 day intervals in increments of 0.5 mg, up to a maximum of 6 mg daily, until optimal relief is achieved without excessive adverse reactions 2
Important Dosing Considerations:
- The long duration of action makes benztropine particularly suitable for bedtime dosing, allowing effects to last throughout the night 2
- Some patients obtain greatest relief with once-daily dosing at bedtime, while others respond better to divided doses 2-4 times daily 2
- Older patients and thin patients generally cannot tolerate large doses 2
Common Pitfalls
- Do not terminate other antiparkinsonian agents abruptly when starting benztropine; if other agents are to be reduced or discontinued, this must be done gradually 2
- When used concomitantly with carbidopa-levodopa or levodopa, periodic dosage adjustment may be required to maintain optimum response 2
- Oral anticholinergics like benztropine can significantly increase dyskinesia and dysphoric mood in some patients, particularly during chronic use 3