Healthy Skepticism Library item: 10978

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

Publication type: news

Sinnema J.
Adverse reactions from mixing drugs with herbal medicines rarely reported
The Edmonton Journal 2007 Jul 21
http://www.canada.com/edmontonjournal/news/bodyandhealth/story.html?id=48aa49a7-a5e4-4c42-8098-d7606b5f8f65&p=1

Full text:

EDMONTON – Pharmacists rarely 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, a new study co-authored by University of Alberta researchers has found.

“Lack of reporting is a major issue of our knowledge of harms,” said Edmonton’s Dr. Sunita Vohra, one of the authors of the study which appeared in this month’s edition of the medical journal The Annals of Pharmacotherapy.

“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, who heads the Complementary and Alternative Research and Education program at the Stollery Children’s Hospital, 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.

For instance, 95 per cent of the pharmacist respondents said they didn’t feel comfortable counselling patients on the possible side-effects of combining garlic with the HIV medication Ritonavir even though reports suggest garlic lowers the concentration of the prescribed drug in the blood. Half had not heard that organ transplant patients taking the anti-rejection drug Cyclosporine along with St. John’s wort — commonly used to fight depression — could cause them to reject their new organ. Many didn’t recognize that St. John’s wort can cause failure of oral contraceptives, or that cranberry juice — taken medically to calm bladder infections — can make the blood-thinning drug Warfarin unstable.

Even so, 47 per cent of 132 pharmacists from a large pharmacy chain in Alberta and British Columbia who responded to the survey said they suspected a potential interaction among their patients.

Yet only two pharmacists reported it to Health Canada, which requests, but does not require, the information from all health-care professionals and patients. In comparison, 19 per cent of those same pharmacists reported drug interactions to the government when it came to traditional prescription and non-prescription medication.

That means only one or two out of every 50 adverse reactions and drug interactions are being reported. With traditional prescription medication, an estimated one out of every 10 reactions are reported.

Vohra doesn’t know why the reporting isn’t being done, but suspects some of the side-effects were not considered serious enough to warrant reporting. Pharmacists are also incredibly busy and might not have time to do the paperwork. In addition, little research has been done on the interactions, so while problems might be suspected, they are not known absolutely.

“It’s not any one group’s responsibility,” said Vohra, who worked with other researchers from the U of A, University of Toronto and Health Canada, which provided the funding.

“It’s a shared responsibility between pharmacists, health-care professionals and patients. It’s critically important for the public to be aware of what the issues are so they can make informed decisions. I think it’s very important to the real lives of Canadians.”

It’s important that people don’t assume all things natural are automatically safe, she said.

“I’m not suggesting they are unsafe,” she said. “I would treat it as if it does have an effect and that means it could also have a side-effect.”

People should make their doctors and pharmacists aware of all the traditional and complementary medicines they are taking, as well as any alternative therapies they are involved with. And health-care workers should routinely ask about the products.

This week, Vohra said she received notice that the Canadian Patient Safety Institute and the Canadian Institutes of Health Research are funding a followup pilot project.

Sixteen volunteer pharmacies across Canada will ask every client about natural health products and record every adverse reaction.

Another researcher in Toronto also is looking at what other education opportunities are needed to teach pharmacists about natural products and their effects. Typically, pharmacists have to rely on the information they received in one lecture during their university training.