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.

Estimate the prevalence of co-prescriptions of antipsychotics and mood stabilizer with clozapine for patients hospitalized in full-time psychiatry.

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.

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).

The combination of psychotropic drugs with clozapine remains a majority practice, which seems to have little connection with existing literature data.

None Declared