Prevalence and predictors of herbal medication use in veterans with chronic hepatitis C

Objective: Herbal therapies are used by a substantial proportion of persons in the United States, and use of these supplements may be even higher in those with chronic liver disease. The aims of this study were to prospectively determine the proportion of US veterans with chronic hepatitis C that are currently taking vitamins and herbal medications and to evaluate factors associated with use of herbal preparations. Methods: Patients with hepatitis C who were seen in the gastroenterology, infectious disease, and primary care clinics at the VA New York Harbor Healthcare System were invited to participate in this prospective study. For comparison, healthy patients without hepatitis C were enrolled from the primary care clinics at the same medical center. Patients were interviewed by trained research coordinators who obtained detailed demographic and clinical data, as well as information on the use of antioxidants (vitamin C and E), multivitamins, and herbal medications. Results: Use of vitamin C (34.8% vs. 19.6%, P < 0.001), vitamin E (25.8% vs. 13.2%, P < 0.001), multivitamins (43.6% vs. 28.0%, P < 0.001), and herbal therapies (21.0% vs. 10.4%, P < 0.001) was significantly higher in the 500 patients with hepatitis C compared with the 250 healthy controls. The most common herbal medications taken by hepatitis C patients were milk thistle (12.2%), ginseng (4.6%), and echinacea (3.0%). After adjusting for age and gender, multivariate logistic regression identified 12 or more years of education (OR 2.7; 95% CI 1.6-4.3; P < 0.001) and annual income of at least $20,000 (OR 2.0; 95% CI 1.3-3.2; P = 0.004) as the only significant predictors of herbal medication use in patients with hepatitis C. Conclusions: The use of herbal preparations is prevalent among veterans with chronic hepatitis C, especially those with higher levels of education and higher incomes. Obtaining a detailed medical history and documentation of the use of these supplements is critical to determine the potential for herbal-drug interactions and hepatotoxicity.