A clinical trial of nifedipine in schizophrenia and tardive dyskinesia

Abstract Effects of the dihydropyridine calcium channel inhibitor nifedipine on chronic schizophrenia and tardive dyskinesia were studied in an 8-week double-blind crossover trial. Four of the ten patients had tardive dyskinesia, and three of these were not receiving neuroleptics. No effects on symptoms of chronic schizophrenia were found using Psychiatric Symptom Assessment Scale ratings. In the four patients with tardive dyskinesia, an average improvement in total abnormal Involuntary Movement Scale scores of 57% was observed. These data suggest that dihydropyridine calcium channel inhibitors may be effective in the treatment of tardive dyskinesia in schizophrenic patients.