Clinical Experience of Clozapine Discontinuation: Comparison between Sulpiride and Thioridazine Switch Group

Lee, Hong Shick; Koo, Min Seong; Cho, Hyun Sang; Park, Il Ho; Kim, Chan Hyung

Abstract

OBJECTIVE
Several reports have found that withdrawal symptoms of clozapine are more severe and common than that of the typical antipsychotics. The objective of this study was to report the clinical experiences of relatively rapid withdrawal of clozapine in the patients with schizophrenia at the end of over a year clinical trial of clozapine.
METHODS
Twenty-three patients with schizophrenia who had been administered clozapine were withdrawn from clozapine by tapering it over 1-2 weeks, depending on clozapine maintenance dose and subsequently switched to sulpiride or thioridazine randomly. Patients were assessed using PANSS, CGI, and Sympson-Augus Rating Scale on the first, third, and last day of clozapine tapering as well as on the first, second, and fourth week of sulpiride or thioridazine.
RESULTS
Fifteen of the 23 patients (65%) relapsed: 5 patients relapsed during the clozapine tapering period and 10 patients relapsed during the switching period to sulpiride or thioridazine. Six of the 9 patients (67%) in the sulpiride switch group relapsed and 4 of the 10 patients (40%) in the thioridazine switch group relapsed. The withdrawal symptoms of clozapine appear faster with a higher relapse rate than the typical antipsychotic drugs.
CONCLUSIONS
Our data suggests that if at all possible clozapine should not be discontinued and for patients who need to be switched to a different antipsychotics for a specific reason, at least 2 weeks of clozapine tapering are recommended. The possibility of cross tapering with another drug should also be considered.