A study conducted in Canada by University of Alberta scientists suggests that natural remedies could cause many more harmful side effects than once thought. Mixing herbal medicines and prescriptions could pose undiscovered health risks because many negative reactions are not being reported or tracked.
Pharmacists seldom report adverse reactions experienced by people who use natural health products along with prescription drugs, even though almost half suspect they have seen patients who have had negative side-effects.
The adverse effects of taking prescription drugs with natural health products are dramatically under-reported or not reported at all, so their potential risks may be underestimated by health-care professionals and the public, the study found.
"People look at risks based on what's known. If it's not being reported, it can't be known," said Dr. Sunita Vohra, an associate professor of pediatrics at the University of Alberta and the study's lead author, which was reported in this month's edition of the medical journal The Annals of Pharmacotherapy. "Lack of reporting is a major issue of our knowledge of harms," "If we don't report what natural products react with what medications, how can we effectively counsel patients in what they should avoid combining?"
Vohra said 71 per cent of Canadians use natural health products, such as St. John's wort, echinacea, Chinese medicines, vitamins, herbal remedies or garlic pills. Many of those people also have chronic health issues and take prescription medications, yet because so little research has been done on the topic, they and health-care providers don't understand the potential risks of mixing the substances.