A pilot study of verapamil in the treatment of tardive dyskinesia

Six patients with severe and stable tardive dyskinesia were treated with verapamil, a calcium channel blocker, in doses ranging from 240 to 400 mg/day. Weekly assessments were made using the Simpson tardive dyskinesia rating scale. Neuroleptic medication was held constant during the 3‐month baseline assessment and during the month of treatment with verapamil. Four of the six patients showed a dramatic response to treatment and a fifth showed a slight improvement. The four good responders were younger and had the tardive dyskinesia for a shorter period of time.