From the FDA Drug Label
In treating extrapyramidal disorders due to neuroleptic drugs (e.g., phenothiazines), the recommended dosage is 1 to 4 mg once or twice a day orally, or parenterally. Dosage must be individualized according to the need of the patient. Some patients require more than recommended; others do not need as much. In acute dystonic reactions, 1 to 2 mL of the injection usually relieves the condition quickly After that, the tablets, 1 to 2 mg twice a day, usually prevents recurrence.
The dose of Benztropine (Benztropine mesylate) for the treatment of Extrapyramidal Symptoms (EPS) is 1 to 4 mg once or twice a day orally, or parenterally 1.
- The dosage must be individualized according to the need of the patient.
- Key considerations for dosage include the type of extrapyramidal disorder, the severity of symptoms, and the patient's response to treatment.
From the Research
Benztropine is typically prescribed at a dose of 1-2 mg orally once or twice daily for the treatment of extrapyramidal symptoms (EPS). For acute dystonic reactions, 1-2 mg can be given intramuscularly or intravenously for rapid relief, as seen in a case report where benztropine 2 mg i.m. resulted in rapid relief of oculogyric crisis symptoms 2. Treatment usually begins with a lower dose of 0.5-1 mg and may be gradually increased as needed based on symptom response. The maximum daily dose should generally not exceed 6 mg. Benztropine works by blocking cholinergic receptors in the central nervous system, which helps restore the balance between dopamine and acetylcholine in the basal ganglia. This mechanism counteracts the parkinsonian-like side effects caused by antipsychotic medications that block dopamine receptors.
Some key points to consider when prescribing benztropine include:
- Patients should be monitored for anticholinergic side effects including dry mouth, blurred vision, constipation, urinary retention, and confusion, which are more common in elderly patients.
- Benztropine should be used cautiously in patients with glaucoma, prostatic hypertrophy, or cognitive impairment.
- For maintenance therapy, the lowest effective dose should be used, and periodic attempts to reduce or discontinue the medication are recommended to assess ongoing need, as suggested by a study that found no difference in EPSE scores and dropout rates between placebo- and benztropine-treated groups 3.
- The use of antiparkinsonian medication, such as benztropine, is essential in the treatment of neuroleptic-induced extrapyramidal symptoms, as it can help alleviate discomfort and improve compliance with therapy 4.
It's also important to note that the incidence of EPS is higher in patients treated with typical antipsychotics compared to atypical antipsychotics, as seen in a study that found a significant difference in EPS incidence between the two groups 5. However, this does not directly impact the dosing of benztropine for the treatment of EPS.