In arteriosclerotic and idiopathic parkinsonism, therapy may be initiated with a single daily dose of 0.5 to 1 mg at bedtime. In postencephalitic parkinsonism, therapy may be initiated in most patients with 2 mg a day in 1 or more doses. In highly sensitive patients, therapy may be initiated with 500 g at bedtime, and increased as necessary. The long duration of action of benztropine makes it particularly suitable for bedtime medication when its effects may last throughout the night. With benztropine patients are better able to turn in bed during the night and to rise in the morning.
Many patients obtain greatest relief with a combination of benztropine and other drugs.
Benztropine may be used concomitantly with levodopa, in which case the dose of each may need to be adjusted. However, if benztropine is continued when Sinemet is introduced, the dosage of benztropine may need to be adjusted. In treating extrapyramidal symptoms due to phenothiazine derivatives or reserpine, 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. When extrapyramidal disorders develop soon after initiation of treatment with phenothiazine derivatives or reserpine, they are likely to be transient.