Herb, supplement use could jeopardize patients undergoing treatment for cancer

Up to half of patients use herbal remedies or dietary supplements during cancer treatment, British researchers report. Because many such remedies pose the risk of side effects and drug interactions, the investigators advise that “patients may require more education on the benefits of and their risk management.”

Of 318 subjects who were surveyed for the study, 51.6% were using these remedies, Dr. Ursula Werneke, at Homerton Hospital in London, and colleagues report in the British Journal of Cancer for January 26. One quarter of these were using substances with psychoactive properties. And even though many were not sure why they were using the agents, more than half had not discussed their use with their physicians.The most frequently used herbs were echinacea, evening primrose oil, ginkgo, milk thistle and essiac. Antioxidants were also popular supplements.Patients with lymphoma were warned by their pharmacies regarding use of echinacea, which could interfere with immune-suppressing therapies. Warnings were also issued for kava kava because of its potential hepatotoxicity, and for fish oil, evening primrose oil, ginkgo and garlic because of their anticoagulant effects. Other concerns were the herbs such as St. John’s wort, whose action on cytochrome P450 may interact with other treatments, possible interference of Siberian ginseng with antihypertensive therapy, and use of supplements at higher than recommended doses. “Antioxidants binding free radicals or remedies increasing photosensitivity may interfere with radiotherapy,” the authors write. They suggest that clinics consider partnering with information providers such as the Longwood Herbal Task Force (www.mcp.edu/herbal), provided by the Massachusetts College of Pharmacy and Health Sciences in Boston. Dr. Werneke’s team also recommend the Natural Medicines Comprehensive database (naturaldatabase.com), which is a paid subscription service.(Source: Br J Cancer 2004;90:408-413: Reuters Health: February 10, 2004: Oncolink)