Outcome Following Clozapine Discontinuation: A Retrospective Analysis

Background: Clozapine is uniquely effective in refractory schizophrenia, but treatment attrition is high. There has been minimal formal study of the outcomes of stopping clozapine, beyond published observations of the time period immediately after cessation. Our aim was to establish medium-term outcome in patients stopping clozapine in normal clinical practice.

Method: This study was a retrospective analysis of all subjects registered with Clozaril Patient Monitoring Service and treated in South London and Maudsley National Health Service (NHS) Trust who stopped clozapine between March 2002 and March 2005 after at least 1 year’s treatment. Case note review was performed to determine relevant information for 1 year before and 1 year after discontinuation of clozapine, including subject details, reasons for stopping, and clinical outcome 1 year after discontinuation. The primary outcome measure was the Global Assessment of Functioning scale.

Results: Thirty-five patients met inclusion criteria. Twelve had died while receiving clozapine. Of those followed up for 1 year after cessation (N = 23), mean Global Assessment of Functioning scores fell by 15 points (95% CI = 6.6 to 24.3; p = .002). Days spent in hospital rose from a mean of 74.1 (SD = 137.3) to 119.8 (SD = 143.5) (p = .214).

Conclusion: Discontinuation of clozapine has a marked negative impact on clinical status. Death is a common cause of clozapine cessation.