Concurrent administration of clozapine and electroconvulsive therapy in clozapine-resistant schizophrenia

Objective: The aim of this article is to critically review all published studies regarding the efficacy and safety of the concurrent administration of clozapine (CLZ) and electroconvulsive therapy (ECT) in CLZ-resistant schizophrenic or schizoaffective patients. Method: A MEDLINE search from January 1980 to July 2005 was conducted. Results: One open-label trial and 6 case studies were located, comprising 21 schizophrenic and 1 schizoaffective patients (12 men and 10 women) with a mean age of 41.9 years. The duration and dosage of CLZ monotherapy before ECT were reported at least 12 weeks and 300 mg/d, respectively, in 10 patients (45.4%). Plasma CLZ levels before ECT were assessed in 12 patients (54.5%), in which only 7 (31.8%) were reported to be higher than 350 ng/mL. The CLZ dosage during ECT ranged from 200 to 900 mg/d (mean, 518.2 +/- 203.3 mg/d). The number of ECT sessions ranged from 2 to 20 (mean, 11.5 +/- 5.4). Application of electrodes was unilateral in 7 patients, bilateral in 10 patients, and mixed in 2 patients. Sixteen patients (72.7%) showed marked improvement whereas 6 patients (27.3%) had moderate, minimal, or no improvement. No predictors of outcome could be isolated. Side effects reported by 5 patients (22.7%) were nausea, tachycardia, hypertension, memory problems, and confusion. Ten patients (45.4%) relapsed during follow-up. Substantial improvement persisted beyond 4 months in only 5 patients (22.7%). Conclusion: Preliminary evidence exists for the safety and short-term efficacy of the concurrent administration of CLZ and ECT in CLZ-resistant schizophrenic or schizoaffective patients.