Amisulpride (AMI) is a popular antipsychotic drug prescribed for the management of schizophrenia. However, patients may experience prolonged corrected QT (QTc) interval. We therefore aimed to assess the risk factors for QTc prolongation during AMI therapy in patients with schizophrenia.
This study retrospectively enrolled 271 patients with schizophrenia. Continuous variables were analyzed with a t test or analysis of variance, and categorical variables were analyzed with a χ2 test. Patients with and without QTc prolongation were compared using a backward stepwise logistic regression analysis to identify the important variables.
Comedication of AMI with clozapine (odds ratio, 3.5 [95% confidence interval, 1.3–9.7]) and decreased renal function (mildly decrease, 3.4 [1.2–10.1]; mild to moderately decreased, 4.8 [1.3–17.3]; moderately decreased, 13.6 [2.0–90.6]) were identified as the independent risk factors of QTc prolongation. The dose-normalized plasma concentration of AMI (plasma concentration per dose) was significantly higher in the QTc prolongation group (z = −1.735, P = 0.015) and renal dysfunction group (F = 16.002, P < 0.001).
Renal function should be monitored in patients prescribed with AMI, particularly in those taking clozapine. Plasma concentration per dose values can be considered as a risk factor of QTc interval prolongation. The founding help clinicians to analyze the risk of QTc prolongation before prescribing AMI and to monitor QTc prolongation during AMI therapy.