The American Psychiatric Association (APA) has updated its Privacy Policy and Terms of Use, including with new information specifically addressed to individuals in the European Economic Area. As described in the Privacy Policy and Terms of Use, this website utilizes cookies, including for the purpose of offering an optimal online experience and services tailored to your preferences.

Please read the entire Privacy Policy and Terms of Use. By closing this message, browsing this website, continuing the navigation, or otherwise continuing to use the APA's websites, you confirm that you understand and accept the terms of the Privacy Policy and Terms of Use, including the utilization of cookies.

×

Objective:

The authors compared the effectiveness of initiating treatment with either clozapine or a standard antipsychotic among adults with evidence of treatment-resistant schizophrenia in routine clinical practice.

Method:

U.S. national Medicaid data from 2001 to 2009 were used to examine treatment outcomes in a cohort of patients with schizophrenia and evidence of treatment resistance that initiated clozapine (N=3,123) and in a propensity score-matched cohort that initiated a standard antipsychotic (N=3,123). Interventions were new initiation of clozapine or a standard antipsychotic medication, defined as no exposure to the new medication in the prior 365 days. The primary outcome was hospital admission for a mental disorder. Secondary outcomes included discontinuation of the index antipsychotic, use of an additional antipsychotic, incidence of serious medical conditions, and mortality.

Results:

Initiation of clozapine was associated with a significantly decreased rate of psychiatric hospital admission (hazard ratio=0.78, 95% CI=0.69–0.88), index antipsychotic discontinuation (hazard ratio=0.60, 95% CI=0.55–0.65), and use of an additional antipsychotic (hazard ratio=0.76, 95% CI=0.70–0.82). Clozapine was associated with significantly increased incidence of diabetes mellitus (2.8% for clozapine vs. 1.4% for standard antipsychotic; hazard ratio=1.63, 95% CI=0.98–2.70), hyperlipidemia (12.9% for clozapine vs. 8.5% for standard antipsychotic; hazard ratio=1.40, 95%CI=1.09–1.78), and intestinal obstruction (0.9% for clozapine vs. 0.3% for standard antipsychotic; hazard ratio=2.50, 95% CI=0.97–6.44).

Conclusions:

In adults with schizophrenia and evidence of treatment resistance, initiating clozapine compared with initiating a standard antipsychotic was associated with greater effectiveness on several important outcomes. Increasing the judicious use of clozapine is warranted together with vigilance to prevent and detect serious medical adverse effects.

Access content

To read the fulltext, please use one of the options below to sign in or purchase access.