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We are living through a meeting of medical paradigms – and how challenging and confusing that is. Holistic remedies and pharmaceuticals sit side by side on our bathroom shelves, and they sometimes combine in our bodies with unhappy results. When you’re mixing and matching, the key to a happy ending is information. For example, don’t take pharmaceuticals with grapefruit juice , which can block your liver’s ability to clear drugs, thus increasing blood levels of many meds beyond intended dosages. As well, ginger and black pepper can speed absorption of many drugs and this may not be what you want.
St. John’s wort clears drugs from your bloodstream faster than they would be otherwise, reducing their effectiveness. This interaction is seen with birth control pills, HIV protease inhibitors, digoxin, warfarin, chemotherapy drugs and some antipsychotics. St. John’s wort may also cause various other side effects in combination with sulfa antibiotics, antidepressants and some anti-inflammatory drugs.
That ubiquitous painkiller aspirin could cause internal bleeding if its ability to “thin” the blood is augmented by herbs like garlic , ginger , ginkgo biloba , horse chestnut or red clover . The same is true if you’re on a prescription anticoagulant containing warfarin (e.g. Coumadin). If you’re taking sleeping pills or anti-anxiety drugs, adding natural remedies like valerian could be over-sedating.
These possibilities are just the tip of a very big iceberg that has not yet been thoroughly researched. Make sure to let your doctor know if you plan to combine meds and natural health products. As well, every accredited pharmacy must own a reference book on herbs and subscribe to a drug information service that can quickly provide the latest reports on possible adverse reactions.
If you do experience unexpected side effects that you think are traceable to a particular remedy or cocktail of remedies, report your concern to Health Canada’s Adverse Drug Reaction program at 1-866-234-2345. Your info may be just what’s needed to spare someone else your pain.
what the experts say
“If my patients take prescription medications, I have to be extra-prudent when prescribing food, vitamins and herbs. All can interact. Most potential drug-herb interactions are unreported. There’s no formal information-sharing system on drug-herb interactions for naturopaths, at least to my knowledge a naturopath need to know which databases to access. I feel empathy for my patients who are less inclined to tell their mainstream doctors about seeing someone like me. (Often), instead of being commended for taking the initiative, they’re chastised for it.”
NORA JANE POPE, naturopath, Toronto
“Many herbs have a gentler and less quick action (than pharmaceuticals), so you tend to have fewer herb-drug interactions (than drug-drug interactions), but that’s a huge generalization. Patients should tell their physician and pharmacist if they’re taking anything else by mouth, any herb or supplement. Even some creams could interact with another drug. Acupuncture or chiropractic can affect the dose of your drug. A UK study found people were less likely to report suspected adverse effects and interactions involving herbs than those involving drugs, because people don’t think herbs can cause adverse effects.”
HEATHER BOON, pharmacist, PhD, assistant professor, faculty of pharmacy, University of Toronto
“We did a study looking at the quality of information consumers receive at retail outlets and found that it was not always as accurate as we’d like. Information regarding potential adverse effects was less forthcoming than would be ideal. In another study, we found patients did not communicate to the prescribing physician that they were also taking a natural health product. They just didn’t appreciate the importance or the need to tell, and because they weren’t asked by their physicians they didn’t offer the information.”
MITCHELL LEVINE, professor, faculty of health sciences, McMaster University director, Centre for Evaluation of Medicines, St. Joseph’s Health Care, Hamilton
“We have standards of practice that absolutely include asking about what other medications or therapies the patient might be taking. We have library requirements for every pharmacy. Pharmacists also have to subscribe to a drug information service. They can call in and ask for information, and herbal products are included in that as well.”
DEANNA WILLIAMS , registrar, Ontario College of Pharmacists
“The Canadian Adverse Reaction newsletter alerts health professionals and consumers to potential signals detected through the review of case reports submitted to Health Canada. The signal triggers a need for further investigation and analysis of a product. The newsletter goes to every doctor through the Canadian Medical Association Journal. The public can subscribe to this service on our Web site (www. hc-sc. gc. ca). It requires a physician to interpret that information. Health care professionals have an important role to play in terms of disseminating this information.”
KRISTA APSE, spokesperson, Health Canada
