Adherence to treatment guidelines in clinical practice: study of antipsychotic treatment prior to clozapine initiation

BACKGROUND: Clozapine is the only antipsychotic drug licensed for treatment-resistant schizophrenia but its use is often delayed. Since previous studies, national guidelines on the use of clozapine and other antipsychotics have been disseminated to clinicians. AIMS: To determine the theoretical delay to clozapine initiation and to quantify the prior use of antipsychotic polypharmacy and high-dose antipsychotic treatment. METHOD: Clinico-demographic data were extracted from the treatment records of all patients commencing clozapine in our centre between 2006 and 2010. RESULTS: Complete records were available for 149 patients. The mean theoretical delay in initiating clozapine was 47.7 months (s.d. = 49.7). Before commencing clozapine, antipsychotic polypharmacy and high-dose treatment was evident in 36.2 and 34.2% of patients respectively. Theoretical delay was related to illness duration (β = 0.7, P<0.001) but did not differ by gender or ethnicity. CONCLUSIONS: Substantial delays to clozapine initiation remain and antipsychotic polypharmacy and high doses are commonly used prior to clozapine, despite treatment guidelines.