Determinants of antipsychotic formulations in schizophrenia and bipolar disorder patients: A retrospective chart review

Aim: Long-acting injectable antipsychotics (LAIs) have significant clinical advantages in the treatment of psychotic disorders; however, there are concerns that LAIs are under-prescribed. Both regional and temporal variations in LAI use have been reported. In addition, it is an object of interest how LAI use is affected by the Coronavirus Disease 2019 (COVID-19) pandemic. Studies focusing on the temporal change in LAIs use and studies investigating the possible changes in LAI usage during the pandemic are few and have been conducted in only two developed countries. In our study, we aimed to determine the frequency of LAI use in our clinic, the change in this frequency over time, and the patients with which characteristics LAIs are preferred. Materials and Methods: Those who applied to our outpatient clinic between 01.01.2009-28.02.2009, 01.01.2019-28.02.2019 and 01.01.2021-28.02.2021; 1646 patients aged 18-65 years who were diagnosed with schizophrenia (F20), schizoaffective disorder (F25), bipolar disorder (F31), or unspecified non-organic psychosis (F29) and using effective doses of antipsychotic medication were recruited. Data collection forms were filled with the information obtained from the patients' polyclinic files. The temporal variation in LAI use was examined by comparing the frequency of LAI use in the three periods studied. The determinants of LAI use were investigated by comparing patients using LAI with patients not using LAI. In addition, in patients using LAI, the clinical status of the patients before using LAI was compared with the period when they used LAI. Also, drug compliance and side-effect profiles of the antipsychotic groups were compared. Results: There was a temporal increase in the use of LAIs and this increase was due to the increase in the use of second generation LAIs (SG-LAI). It has been observed that the frequency of UEAP use is not affected by the pandemic period. LAIs were preferred in all diagnostic groups, in patients with a worse clinical status. In the schizophrenia group, comorbid psychiatric diseases, comorbid physical diseases, criminal history and treatment compliance; in the schizophrenia spectrum disorders group (F20+F25+F29), comorbid psychiatric diseases, comorbid physical diseases, hostility-aggression and treatment compliance; in the bipolar disorder group, hostility-aggression, sub-threshold affective symptoms and CGI-S score were predictors of LAI use. When compared before and after LAI period, the use of LAI increased in all diagnosis groups with an increase in the use of multiple antipsychotics; It was observed that it was associated with a decrease in aggression, the number of hospitalizations and the duration of hospitalization, as well as a decrease in the number of suicide attempts in the schizophrenia group. In drug comparisons, compliance with SG-LAIs was found to be higher compared to both first-generation LAIs (FG-LAI) and OAPs, and there was no difference between FG-LAIs and OAPs in terms of drug compliance. When the side effect profiles of FG-LAIs and SG-LAIs were compared; parkinsonism and acute dystonia were detected more frequently in FG-LAIs, while hyperprolactinemia and sexual dysfunction were detected more frequently in SG-LAIs. Conclusions: Our study is the first to investigate both the temporal variation in LAI use and the impact of the pandemic on LAI use in a developing country. The findings show that, similar to developed countries, the use of LAI in our clinic has increased over time and this increase is due to SG-LAIs. Our study is important in terms of showing that the use of LAI can be successfully maintained in countries more heavily affected by the pandemic. In our research on the determinants of LAI use, it was found that LAIs are preferred in patients with worse clinical status. This is the first study that we know of investigating the temporal variation in LAI use and the determinants of LAI use in the context of bipolar disorder. It has been found that the use of LAI in patients with bipolar disorder also increases over time, and LAIs were preferred in patients with worse clinical status. Expanding the use of LAI to patients with better clinical status may also benefit these patients from the potential advantages of LAIs.