Clozapine: prevalence and modalities of associations with antipsychotics and mood stabilizer in French psychiatric hospitals. Multicenter survey on a given day

Introduction Clozapine is indicated for resistant schizophrenia as monotherapy. However, the response is inadequate in 40-70% of patients. In this context, the combination of clozapine with a second antipsychotic or a mood stabilizer is a strategy frequently used to potentiate its effects ( Barlatier, A. (2014) Human Medicine and Pathology. Doctoral thesis, University). However, the level of evidence for these practices remains low, and data on the prevalence of such combinations in France are limited. Against this backdrop, collaboration between a national multi-professional network operating in various public and private mental health establishments (the PIC network) and a regional psychiatric research federation (FERREPSY Occitanie) enabled the study of the prevalence and modalities of these associations in a large panel of French psychiatric establishments. Objectives Estimate the prevalence of co-prescriptions of antipsychotics and mood stabilizer with clozapine for patients hospitalized in full-time psychiatry. Methods Observational cross-sectional study conducted on a given day in December 2023 in 30 participating centers that are members of the PIC network and/or FERREPSY. Results The computerized records of 795 patients were analyzed by the referring pharmacists at the participating centers. 78.4% of patients had at least one antipsychotic in association with clozapine. 64.5% of antipsychotics associated with clozapine were conventional antipsychotics. Among atypical antipsychotics, aripiprazole was combined with clozapine in 9.9% of patients, amisulpride in 10.7%, risperidone in 8.2%, olanzapine in 4.3% and quetiapine in 3%. For mood stabilizer, the combination of clozapine with valproate was the most commonly used combination (23.64% of patients), ahead of lithium salts (15.6% of patients) and lamotrigine (10.1% of patients). Conclusions The combination of psychotropic drugs with clozapine remains a majority practice, which seems to have little connection with existing literature data. Disclosure of Interest None Declared