Initial dose is 1 mg twice daily, gradually increased over several days according to the needs of the patient. The usual optimum maintenance dosage varies from 3 to 12 mg daily in divided doses. Initial dose for idiopathic parkinsonism is 2 mg three or four times daily increased according to the needs of the patient to a maximum of 16 mg in 24 hours. The dose for drug-induced extra pyramidal symptoms is 2 mg one to three times daily.