Global patterns of clozapine prescribing: An international comparison of prescribing indications across 15 regions.

Evidence of clozapine's transdiagnostic benefits beyond schizophrenia spectrum disorders (SSDs) is increasing. Whether this has impacted clozapine usage patterns in practice is yet to be assessed. This study aims to examine the range of indications associated with clozapine prescribing internationally and explore cross-country variation in the distribution of utilisation across diagnostic categories. Information on prescribing indication was obtained using the IQVIA Multinational Integrated Data Analysis System (MIDAS) Disease Insights database. The database contained information on indications recorded for clozapine prescribing in 55 countries and 15 regions. Prescribing indications for clozapine were obtained by IQVIA through a combination of (1) electronic medical records, (2) prescription and claims data, and (3) patient medication records. Results were analysed descriptively. Collectively, prescribing of clozapine was most commonly recorded within SSDs (82.3%). Clozapine prescribing within non-SSDs accounted for approximately 18% of all indications recorded; mood disorders (13.6%), anxiety disorders (2.5%), movement disorders (1.1%), epilepsy (0.4%), and dementia (0.1%). Bipolar disorder (59.3%) was the most commonly recorded prescribing indication within mood disorder management. Substantial interregional variation in utilisation trends were apparent. Recorded clozapine prescribing within non-SSDs was highest in African and Asian regions, accounting for an average of 34.3% and 21% of all recorded indications within each region respectively. In conclusion, substantial use of clozapine outside of SSDs was identified, with approximately 1 in 5 recorded indications occurring for a non-SSD indication. International guidance considering the availability and quality of evidence supporting clozapine use more broadly in psychiatry is now required to promote rationale, evidence-based use.