Dangerous Duo: Taking Supplements with Prescription Meds

shutterstock_343421621 Dietary supplements via Shutterstock

Millions of Americans are big believers in the power of dietary supplements. Yet, so many individuals remain completely ignorant about the inherent risks associated with them.

In many cases, over-the-counter vitamins and supplements can interfere with prescription drug medications, thus altering treatment entirely for some serious health issues that include depression, infections and certain cancers.

Take echinacea, which people mistakenly believe treats the common cold. But the seemingly-harmless supplement can have life-threatening effects when taken simultaneously with certain chemotherapy drugs. Depending on the individual, echinacea will interfere by making a prescribed dose too high (so that it becomes toxic) or too low (thus rendering it useless).

And then there’s calcium, used to promote bone health, which binds with antibiotics so they are not absorbed, while Gingko Biloba -- hypothesized to sharpen memory and cognition -- interferes with antidepressants and certain heart medications.

“Many of these supplements change enzymes that metabolize drugs. They raise them up or raise them down,” said Dr. David Agus, director of USC Norris Westside Cancer Center, in an interview with CBS News. “So when you’re taking a drug, whether its for blood clotting, chemotherapy, for a thyroid disorder or for something else, it can make the level higher or lower so the drug may not work or you get undue side effects.”

And while doctors and pharmacists are required to disclose potential drug interaction side effects of medical prescriptions, nothing of the sort exists for vitamins and supplements. This is largely because the runaway $36 billion industry is unregulated by the Food and Drug Administration.

Here at ACSH, we have discussed extensively the inherent problems with the unregulated dietary supplements industry.

So, it becomes the responsibility of the patient to be completely transparent and disclose any and all vitamins and supplemental drugs one is taking, to ensure that there will be no interaction effects with what a doctor prescribes.

Further complicating this issue is that while 53 percent of Americans report taking dietary supplements, no real empirical evidence exists to support taking them in the first place.

"There's a potential downside and not yet a significant upside," Dr. Angus added, "so we need to start having these discussions to make sure."

Dr. David Seres, ACSH friend and Director of Medical Nutrition at Columbia University Medical Center, supports the sentiment expressed by Dr. Agus. He wrote in CNN opinion that OTC dietary supplements are not quite the "amazing panacea that we have been led to believe.”

But that's a whole other story.