Concurrent Use of Herbal Medicines and Prescription Drugs and Potential Herb-Drug Interactions: A Cross-Sectional Study

Abstract

Background: Herbal medicine use is widespread amongst people with chronic conditions, and this could be a potential concern for herb–drug interactions. This study aimed to evaluate the prevalence of concurrent herbal medicine use and factors associated with possible interactions among adult patients who were on long-term pharmacotherapy. Method: In this study, 220 adults attending outpatient departments at a tertiary care hospital and using prescribed medicines for ≥3 months were included. Data on chronic diseases, prescribed and herbal medicines, medication disclosure, information sources, self-medication, and adverse effects were collected through interviewer-administered questionnaires and medical records. Potential herb–drug interactions were identified using published evidence. Descriptive statistics and multivariable logistic regression were performed, with p < 0.05 considered statistically significant. Results: The mean age was 47.5 ± 13.2 years, and 58.2% were female. 96 (43,6%) of participants reported using herbs concurrently, and 28 (29.2%) disclosed that they used herbs to their physicians. 37 (38.5%) of herbal users were identified as having potential herb-drug interactions. The most frequently reported adverse effects were gastrointestinal symptoms 16 (16.7%), followed by altered glycaemic control 11 (11.5%). Independent predictors were use of three or more prescribed medicines (AOR=3.18, 95% CI: 1.45-6.98; p=0.004), physician unawareness (AOR=2.81, 95% CI: 1.18-6.69; p=0.019), age ≥60 years (AOR=2.39, 95% CI: 1.04-5.47; p=0.041), and self-medication (AOR=2.22, 95% CI: 1.01-4.91; p=0.047).  Conclusion: Use of herbal medicine was widespread, often unacknowledged, and had potential interaction risks. Medication safety should be adopted through routine enquiry and pharmacist-supported medication review.