Association of antipsychotic formulations with sudden cardiac death in patients with schizophrenia: A nationwide population-based case–control study

The aim of this study was to clarify the association between various antipsychotic formulations-oral-daily antipsychotics (OAPs), long-acting injectable antipsychotics (LAIs), and their combination-and the risk of sudden cardiac death (SCD). We conducted a nationwide population-based case-control study using data from 2011 to 2020 from the National Health Insurance Research Database and multiple-cause-of-death data from Taiwan. The study included patients with a new diagnosis of schizophrenia who were followed for SCD occurrence until 2020. Cases and controls were frequency-matched at a 1:4 ratio by age, sex, and year of new schizophrenia diagnosis. Compared with the use of OAP monotherapy, the use of LAI and OAP combination (OR = 1.91) and LAI monotherapy (OR = 1.45) were associated with an increased risk of SCD. Additionally, cardiovascular comorbidities (adjusted OR = 11.15) were identified as a significant risk factor for SCD. This study revealed the following hierarchy of SCD risk associated with antipsychotic formulations (listed from lowest to highest risk): nonuse of antipsychotics, OAP monotherapy, LAI monotherapy, and their combination. These findings underscore the importance of assessing cardiovascular disease history before LAIs are prescribed to patients with schizophrenia and indicate that physicians should avoid prescribing combined antipsychotics when using LAIs.