Risk of Serious Ventricular Arrhythmia in Users of Gastrointestinal Medications: A Retrospective Cohort Study in China

Clinical data have demonstrated prolongation of the QTc interval associated with domperidone use. The risk of serious ventricular arrhythmias (SVA) in clinical practice in China has not been investigated. The incidence of SVA and all-cause cardiac arrest associated with medications for gastrointestinal disorders in China was assessed in a retrospective cohort study using information from electronic medical record databases from the Xijing and Guangzhou general hospitals. Inpatients and outpatients with at least one prescription for domperidone, mosapride/itopride, metoclopramide, a proton pump inhibitor (PPI), or histamine H2 receptor antagonist were identified in the hospital databases from January 1, 2009 to December 31, 2014. The inpatient exposure cohorts included 66,282 inpatients at Xijing and 23,643 inpatients at Guangzhou hospitals. There were 67 cases of SVA and two cases of SVA at the respective hospitals during the study period. Three cases (all at Xijing) occurred in patients prescribed domperidone (incidence rate 2.9/100 person-years (PYs), 95% CI 0.9–9.0) compared to 1.3/100 PYs (95% CI 0.2–8.9) for mosapride/itopride and 5.6/100 PYs (95% CI 4.4–7.2) for PPIs. The hazard ratio adjusted for age, sex, and co-morbidities for SVA in patients prescribed domperidone compared to PPIs was 0.79 (95% CI 0.25–2.56). There were 44 cases of all-cause cardiac arrest at Xijing and 21 at Guangzhou hospital. Three patients had received domperidone and all had underlying cardiovascular diseases. SVA and cardiac arrest are very rare events in patients prescribed medications for gastrointestinal disorders in China. We found no evidence that domperidone carried a higher risk of SVA compared to other gastrointestinal medications.