Antipsychotic drug dose in real-life settings results from a Nationwide Cohort Study

Despite national and international recommendations and while there is no evidence for increased efficacy of higher doses, several studies suggested that the prescribed doses in routine practice are higher than the maximal recommended doses in 20–40% of schizophrenia patients worldwide. Methods: the aims of the present study were: (1) to describe the patterns of antipsychotic daily dose prescriptions in routine clinical practice in a large and representative cohort of French schizophrenia patients and, (2) to study the characteristics of patients receiving higher doses. Results: in all cases, regardless of the antipsychotic treatment used, the average dose was greater than 1.0 defined daily dose (DDDeq), which is the average recommended dose. For SGA, the mean DDDeq ranged from 1.2 for aripiprazole to 1.6 for olanzapine and clozapine, respectively. For a given patient, the mean ± S.D. total daily cumulative dose (TCD) of antipsychotic was 1.9 ± 2.4 DDDeq. A “high dose” was defined as a TCD ≥ 1.5 DDDeq, 789 (45.2%) patients received a “high dose”. Patients in the “high dose” group were more frequently suffering from a more severe paranoid schizophrenia, had more often a comorbid antisocial personality disorder and/or a substance use disorder. Conclusions: the present study suggests that in France, antipsychotic drugs doses prescribed by psychiatrists are higher, compared to other countries. All recommendations agree on the fact that the preferential dose should be the “minimum-effective” dose. Optimizing prescribing practices would be important to optimize the benefit/risk ratio and to minimize the risks side effects.