Are Your Herbal Supplements Interacting With Your Medicines?
Many people take herbal or dietary supplements along with their prescription medicines. But medicines and supplements may interact in harmful ways!
Some supplements can decrease the effects of medicines, while others can increase the effects, as well as cause unwanted side effects.
The medicines affected have a ‘narrow therapeutic index’, which means that if the amount of the drug is even a little too low or too high, it can cause big problems.
Warfarin (Coumadin) is one such medicine. When taken with certain herbal supplements, such as Asian ginseng or St. John’s Wort (and possibly ginger), you may need to be closely monitored.
St. John’s wort, for example, interacts with many types of drugs. In most instances, it speeds up the processes that change the drug into inactive substances, leading to a decrease in drug levels in your body.
Other medicines with a narrow therapeutic index include digoxin (heart), theophylline (asthma), lithium (anti-depressant), acetaminophen (pain killer) and gentamicin (antibiotic).
The herb-drug interaction potential is high for St. John’s Wort, Asian ginseng, Echinacea, ginkgo (high dose) and goldenseal; But low for black cohosh, ginkgo (low dose), garlic and kava supplements.
Take an Inventory
If you take any of the described medicines and herbal supplements, use our free Medication Inventory form to make a list of everything you take.
List how often you take them, and the doses you take.
Then ask for a review by your doctor or pharmacist for any harmful interactions. You may find you want to modify your supplement regime.
Do Your Own Research
Learn more about herb-drug interaction potentials at:
• Herb-Drug Interactions: What the Science Says. National Institutes of Health/National Center for Complementary and Integrative Health.
• About Herbs, Botanicals & Other Products“ at the Memorial Sloan Kettering (MSK) website (one of our favorites).