Use of a Combination of Clozapine With a Long-Acting Injectable Antipsychotic: A Retrospective Study

About one-third of patients fail to respond to clozapine and require augmentation. Among the various augmentation strategies, the use of long-acting injectable (LAI) antipsychotics has been evaluated in a few studies, but the data remain inconclusive. Furthermore, there is a lack of data on the use of a combination of clozapine and LAI from developed countries. This retrospective study aimed to evaluate the impact of clozapine and LAI combination on symptom profile, rehospitalization rate, and functioning in the Indian setting.

For this study, treatment records of patients on clozapine were reviewed for the use of a combination of clozapine and an LAI antipsychotic. Patients who had received a combination of clozapine and LAI were included in this study. The information available in the treatment records was used to rate the patients on the clinical global improvement (CGI) scale retrospectively to evaluate the beneficial effect of the combination.

Out of the 1102 patients who received clozapine while in contact with our services, 13 patients had received a combination of clozapine and an LAI. In 8 patients, LAI was started after an adequate clozapine trial, and in 5 patients, clozapine was added to the ongoing LAI antipsychotic medication. At 3 months, 12 patients were rated as "much improved," and 1 patient was rated as "very much improved" on the CGI. At the last follow-up assessment, at 6 months to 6 years, the improvement was rated as "very much improved" for 9 patients, and "much improved" for 3 patients. While on the combination, only 2 patients required further inpatient care. The combination also led to a reduction in the number of relapses and an improvement in functioning.

The present study suggests that combining LAI with clozapine leads to improvement in psychopathology and functioning.