Prediction of early relapse after pimozide discontinuation by response to d-amphetamine during pimozide treatment.
Thirteen schizophrenic patients underwent a d-amphetamine infusion while being treated with pimozide, an antipsychotic agent and a relatively specific dopamine (DA) blocker. Six patients who showed an acute increase in psychosis with d-amphetamine relapsed within 3 months after pimozide withdrawal. Of the seven patients who did not change in psychosis with d-amphetamine, six did not relapse after pimozide discontinuation (Fisher's exact test, p less than 0.005). Retrospectively, the psychosis-inducing effects of d-amphetamine were found to be predictive of psychotic exacerbation following subsequent pimozide withdrawal. Pimozide failed to block the psychotogenic effects of d-amphetamine in six patients indicating that other mechanisms besides DA may play a role in psychotic decompensation. The d-amphetamine infusion paradigm should be studied further to determine its clinical value for identifying which schizophrenic patients are at risk for relapse after discontinuation of neuroleptic treatment.
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010868:Pimozide / Q000008:administration & dosage / Q000627:therapeutic use*; D011954:Receptors, Dopamine / Q000187:drug effects; D012008:Recurrence; D012189:Retrospective Studies; D012306:Risk; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology; D012565:Schizophrenic Psychology
D011954:Receptors, Dopamine; D010868:Pimozide; D003913:Dextroamphetamine; D004298:Dopamine