Acute hypertension after abrupt withdrawal of antipsychotic medication

An 18-year-old patient with catatonic schizophrenia developed hypertension when administration of antipsychotic medication was discontinued. Elevated blood pressure was sustained for three days until it was discovered that intramuscular administration of benztropine mesylate immediately reduced it to normal. The fact that the hypertension was not noted earlier while the patient was receiving the antipsychotic drugs suggests that it was a withdrawal phenomenon.