A risky combination: prescription drugs and herbal supplements

The potential for prescription drugs to interact with herbal supplements is real, and withholding information about what supplements you take could pose potentially harmful effects.

An example of this can be seen with St. John’s wart  – a natural remedy known for treating mood disorders. Many people are weary of taking antidepressants and choose instead to use the herbal supplement since it is strong enough to relieve mild to moderate depression. But new research shows it is also the remedy most likely to interact with pharmaceutical drugs.

A new report found that St. John’s wart is known to interfere with 147 different medications — from cholesterol lowering statins to the blood thinner warfarin — after reviewing 85 studies published in the International Journal of Clinical Practice.

Magnesium was also found to have a high number of interactions with drugs at 102, along with calcium at 75, iron at 71 and ginkgo biloba at 51.

These interactions can either amplify or reduce the effect of certain prescription drugs, and the study identified 17 per cent could pose a major health risk such as a hypertensive crisis, excessive bleeding or a coma.

Study author Simon Pickard noted that drug interactions with herbal remedies are tremendously under-reported, generally because they are rarely harmful enough to require a trip to the doctor. The majority of interactions are small and can be avoided by simply making your pharmacist aware of any supplements you are taking when picking up a prescription, and following directions.

Less than a third of patients inform their health care provider when they are taking supplements, which leaves room for potentially harmful interactions to happen.

For pharmaceutical drugs, warfarin had the highest number of reported interactions with supplements. Incidents with insulin, Aspirin, digoxin and ticlopidine were also heavily reported.

“We were able to hone in on those disease states where we know the most about interactions and contraindications. We should be more aware with patients that have these conditions that they will potentially encounter problems if they are using [certain] herbs or dietary supplements,” Pickard wrote in the study.

In recent years, herbal remedies have become an increasingly popular choice for those looking to keep their bodies free of chemicals. “Survey after survey shows that large proportions of the population are trying ‘natural’ remedies for illness-prevention, all sorts of ailments, diseases or for states of reduced well-being. Most experts therefore agree that the potential for such interactions is substantial,”  Professor Edzard Ernst, Emeritus Professor at the University of Exeter wrote in an editorial on the review.

While both natural and lab created medicine have their benefits – the most important thing you can do for your health is to make sure your doctor and pharmacist are aware of what you are taking. It is the only way to prevent potential interactions that could be harmful to your health.

For more information on supplement interactions, click here.

Sources: Wiley, Globe and Mail

Photo ©iStockphoto.com/Miodrag Gajic

The Zoomer Report: Herbal Menopause Remedies
Surviving sniffle season
Foods to ease the pain
The herbal harvest