INTRAVENOUS BENZTROPINE AND PROPRANOLOL CHALLENGES IN TARDIVE AKATHISIA

We challenged five patients suffering from tardive akathisia (TA) with intravenous benztropine (2 mg), propranolol (1 mg) and placebo (salin e) using a random, double-blind cross-over design to examine the effec ts of the drugs on the subjective, objective and global manifestations of neuroleptic-induced akathisia. Benztropine produced a marginally s ignificant, and propranolol a significant improvement in the overall m anifestations of the disorder. The patients demonstrated a considerabl e placebo effect and marked variation in their responses to the drugs. The implications of these findings for the pathophysiology of TA in r elation to acute akathisia and tardive dyskinesia are discussed.