Off-label use of antipsychotics in the community pharmacy: the sex differences

Abstract

Antipsychotic drugs are generally registered for treating schizophrenia, psychosis, mania, and conditions of severe (locomotor) agitation. In common practice, however, they are prescribed in a wide range of different psychiatric disorders. We conducted a retrospective, exploratory study to examine off-label use of antipsychotics and possibly sex differences. We defined antipsychotic use as quasi-label when used in non-registered disorders that have psychosis as an inherent co-morbidity. When antipsychotics were prescribed in disorders that are generally not known with psychosis, we defined this as off-label use. In this study, we combined pharmacy records with data from general practitioners in order to evaluate the range of diagnoses for which antipsychotic drugs are used. We focused on sex differences in type of disorder and in prescribed dosages of antipsychotic drugs. Among 97 male and 95 female antipsychotic users, we could classify women significantly more often as on-label antipsychotic drug users compared with men. Most often, this occurred with typical antipsychotic drug treatment. While female patients used equal dosages for on-label and quasi-/off-label indications, we found that male patients used significantly lower dosages in quasi-/off-label indications compared with on-label indications. We suggest elaborate future research on the characteristics of quasi- and off-label antipsychotic drug use in order to define effective and safe use of antipsychotic drugs among off-label indications.