Pharmacological characterization of tardive akathisia.

A patient with tardive neuroleptic-induced akathisia was investigated with multiple pharmacological challenges. It was noted that the patient responded positively to benztropine, bromocriptine, and propranolol, and negatively to physostigmine, and showed little or no response to discontinuation of neuroleptics and challenges with metoclopramide, metoprolol, atenolol, and clonidine. The implications of this pharmacological characterization for the understanding of the pathophysiology of tardive akathisia in relation to acute akathisia and tardive dyskinesia are discussed.