EFFECTS OF NIFEDIPINE, A CALCIUM-CHANNEL ANTAGONIST, ON COGNITIVE FUNCTION IN SCHIZOPHRENIC-PATIENTS WITH TARDIVE-DYSKINESIA

We examined whether nifedipine, a calcium channel antagonist, added to a stable regimen of neuroleptic medication would affect cognition in patients with chronic schizophrenia or schizoaffective disorder who ha d tardive dyskinesia. Fifteen patients with tardive dyskinesia were tr eated with nifedipine (60 mg daily) or matching placebo for 4 weeks an d then were crossed over from nifedipine to placebo or from placebo to nifedipine for another 4 weeks. At the end of each 4-week phase of th e study, the patients performed a rotary pursuit test of procedural le arning and a dementia scale assessing general cognitive abilities. Nif edipine improved performance in the rotary pursuit test and conceptual abilities in the dementia scale compared with placebo, but only for p atients who first were exposed to the tests during the placebo conditi on. These results provide preliminary evidence that calcium channel an tagonists might enhance learning and memory in schizophrenic patients with tardive dyskinesia.