DRUG-DRUG INTERACTIONS IN OUTPATIENT HYPERTENSION PRESCRIPTIONS AT PRIMARY HEALTHCARE CENTERS IN A VIETNAMESE PROVINCE: A CROSS-SECTIONAL STUDY

Tóm tắt

Background: Hypertension is one of the most prevalent chronic diseases worldwide and in Vietnam, representing a major public health burden due to its association with cardiovascular morbidity and mortality. Patients with hypertension frequently receive multiple medications because of combination therapy and the presence of coexisting comorbidities. Polypharmacy may increase the risk of clinically significant drug-drug interactions (DDIs), which can affect treatment safety, reduce therapeutic effectiveness, and increase healthcare costs. Therefore, identifying and monitoring potential DDIs in hypertensive patients is essential, particularly in primary healthcare settings where long-term treatment is commonly provided. Objective: This study aimed to evaluate prescribing patterns and the prevalence of potential drug-drug interactions in outpatient hypertension management at primary healthcare facilities in Chau Thanh district, Dong Thap province, Vietnam, in 2025. Materials and methods: A cross-sectional descriptive study was conducted using 600 outpatient prescriptions systematically sampled from 12 commune health stations. Potential DDIs were identified using two electronic databases, DRUGS.COM and MICROMEDEX. Only interactions with concordant classification and moderate or higher severity in both databases were included in the analysis. Results: Antihypertensive monotherapy was the most commonly prescribed regimen, accounting for 93% of prescriptions. Calcium channel blockers (CCB) were the most frequently used drug class (61.5%), with amlodipine being the most commonly prescribed (56.3%), followed by angiotensin receptor blockers (ARB) (24.3%), angiotensinconverting enzyme inhibitors (ACEi) (13.8%), and beta-blockers (BB) (0.5%). Moderate interactions were the most common severity level identified in both databases. Clinically relevant DDIs consistently identified across both databases were observed in 31.7% of prescriptions. The most frequent interacting drug pair was enalapril combined with metformin (41%). Conclusion: Potential drug-drug interactions are common in outpatient hypertension treatment. Continuous and individualized monitoring of DDIs is essential to optimize medication safety and therapeutic effectiveness at the primary care level.