Potential benefits of combining two long-acting injectable antipsychotic: a retrospective study.

The aim of this study was to evaluate the efficacy and tolerability of the combination of two long-acting injectable antipsychotics (LAIA) in psychiatric disorders, especially in schizophrenia. Eighty-three patients treated with dual LAIA were included in the study by retrospective screening from the hospital registration system. The present study was designed as an observational, retrospective, naturalistic mirror-image study. The number of hospitalizations before and after switching to dual LAIA was compared in patients who received oral antipsychotics and single LAIA during the study period. In addition, it was analyzed which was the preferred dual antipsychotic combination. Of the patients, 44.6% had schizophrenia, 41.0% had schizoaffective disorder, and 14.4% had other psychiatric disorders. The number of patients receiving oral treatment prior to dual LAIA use was 80 (96.4%). Data on dual LAIA regimens showed that 31.3% were receiving paliperidone and aripiprazole, 24.1% were receiving paliperidone and flupenthixol, 18.1% were receiving paliperidone and zuclopenthixol, and 26.5% were receiving the other combinations. After dual LAIA treatment, there was a significant decrease in the number of hospitalizations compared to before (from 5.95 to 0.99, p<0.001). In addition, while the number of patients who did not require hospitalization in the pre-treatment period was 10.8%, it reached 48.1% in the post-treatment period (p<0.001). No significant adverse effect related to the use of dual LAIA was observed in any patient during the treatment period. The use of dual LAIA instead of oral antipsychotics or single LAIA in chronic psychotic patients with poor social support and irregular medication use is thought to reduce hospitalization and related treatment costs and regularize medication use.