Abstract
BACKGROUND: Domperidone is widely prescribed for gastrointestinal motility disorders and nausea-vomiting but is associated with serious cardiac adverse events, leading to regulatory restrictions on its indications, dosage, and duration. However, passive regulatory notifications alone often fail to translate into safer real-world prescribing practices. OBJECTIVES: To evaluate the long-term real-world effectiveness of an integrated prescribing clinical decision support system (CDSS) combined with clinical pharmacist-led interventions in improving the safety and appropriateness of domperidone prescribing. METHODS: A 10-year interrupted time series (ITS) study was conducted including all 51 437 inpatient and outpatient domperidone prescriptions issued between June 2015 and December 2025 at a large tertiary hospital in Vietnam. Sequential interventions were implemented: real-time CDSS alerts for contraindicated drug-drug interactions and daily maximum dose exceedance combined with pharmacist-led audit-feedback targeting dose errors (April 2021), updating the interaction database and pharmacist-led audit-feedback interventions targeting drug-drug interactions (January 2022), and pharmacist-led educational and audit-feedback interventions targeting treatment duration (September 2023). Monthly prescribing error rates were analyzed using segmented quasi-binomial regression with Newey-West robust standard errors. RESULTS: Prior to intervention, prescribing errors exhibited significant increasing baseline trends for contraindicated drug-drug interactions and maximum daily dose exceedance, whereas prolonged treatment duration errors showed a gradual but significant decreasing trend (P < .001). CDSS implementation alone was associated with a transient increase in contraindicated drug-drug interactions, followed by a significant reversal in trend. Subsequent pharmacist-led active monitoring resulted in a marked and clinically meaningful reduction in contraindicated interaction errors (trend change OR 0.810; 95% CI 0.766-0.857; P < .001) and a 93% crude risk reduction (RR 0.07; 95% CI 0.05-0.09). For maximum daily dose exceedance, the integrated intervention produced an immediate 72% reduction (OR 0.279; 95% CI 0.128-0.609; P = .001) and near-complete reduction of overdose errors (RR 0.003; 95% CI 0.001-0.008). A pharmacist-led educational and audit-feedback intervention produced an immediate 94.5% reduction in prolonged treatment duration errors (OR 0.055; 95% CI 0.018-0.168; P < .001). CONCLUSIONS: Passive regulatory restrictions alone were insufficient to improve domperidone prescribing safety. An integrated CDSS and clinical pharmacist-led intervention model achieved rapid, clinically meaningful, and durable reductions in major prescribing errors and provides an adaptable, evidence-based framework for medication safety management in similar healthcare settings.