Abstract: Objective To explore the incidence and determinants of sinus bradycardia caused by amisulpride and provide a reference for rational medication. Methods The medical records of inpatients taking amisulpride between January 15, 2024 and January 15, 2025 were retrieved from the hospital information system. The effects of gender, age, BMI, medical history, daily dose, concomitant medications, basal heart rate and baseline blood potassium levels on the occurrence of sinus bradycardia were investigated. At the same time, the incidence and the dosage when sinus bradycardia occurred were calculated. Single factor analysis and multivariate logistic regression were used to analyze the contributors. Results A total of 215 inpatients were included in this study, 72 of whom had sinus bradycardia, and 16 were complicated with arrhythmia, so the incidence rate was 33.49%. According to the Naranjo scale, 15 of these cases were probably related to amisulpride and 57 were possibly related. Thirty-nine of these patients were treated with amisulpride at doses of over 800 mg·d^-1, 24 at doses that ranged from 400 mg·d^-1 and 800 mg·d^-1, and 9 at doses of less than 400 mg·d^-1. Single factor analysis showed that there were statistically significant differences in basal heart rate, types of combined drugs and combinations with clozapine (all P<0.05). The results of multiple logistic regression analysis suggested that basal heart rate and clozapine were significantly associated with sinus bradycardia caused by amisulpride (all P<0.05). Conclusion Patients should undergo electrocardiogram examinations before using amisulpride. High doses of amisulpride are more likely to cause sinus bradycardia. In case of slow basal heart rate, patients ought to be given other antipsychotic drugs. The dose or type of drugs should be adjusted along with changes in the electrocardiogram to ensure safe and effective medication.

Key words: Amisulpride, Clozapine, Sinus Bradycardia, Incidence, Contributors, Basal Heart Rate