tiny, plastic, anaimals

Diet supplements get popular, increase risk of drug interaction

Mar 12 2018

The number of people using dietary supplements increases each year. Nearly 1 in 6 older adults are at risk of their dietary supplements interacting with other prescription medication and over-the-counter drugs.

Dietary supplements are big business — an estimated $36.7 billion worth of dietary supplements were sold in 2014, according to the National Institutes of Health. Supplements are actually considered a food product, so they are not regulated in the same way as drugs by the Food and Drug Administration. This puts them in a bit of a gray area of health and wellness claims.

Roughly 70 percent of adults in the country said they were supplement users in a study conducted by the Council for Responsible Nutrition. The organization’s five-year study found 64 to 69 percent of adults used some kind of dietary supplement. The study, which included about 2,000 participants each year from 2007 to 2011, revealed between 28 to 36 percent of the participants were taking multiple dietary supplements. The most common reasons? Overall health and wellness and to fill nutrient gaps in the diet. The most commonly used supplements were multivitamins, omega-3 or fish oil, calcium, vitamin D and vitamin C.

Researchers found that supplement use increased with age and is more common in women than men.

While 64 percent of men reported being supplement users, 74 percent of women said they used some form of supplements, according to the 2011 survey. The survey also revealed 78 percent of people age 55 and older were supplement users. Between 60 and 70 percent of the population aged 18 to 54 reported using dietary supplements.

Potential interactions = hidden dangers

Edmund Pezalla, M.D., M.P.H., vice president and national medical director of Pharmaceutical Policy and Strategy at Aetna, said dietary supplements can help as part of a well-rounded diet, but people should be aware of potential interactions.

An estimated 1 in 6 older adults in the United States are at risk of a major drug interaction, according to a study published in the Journal of the American Medical Association in March 2016. The study, which looked at the changes in prescription, over-the-counter medication and dietary supplement use among older adults in the United States in 2005 and 2011, suggests drug interaction is a growing public health problem.

15 percent of older adults at risk of drug interactions in 2011; dietary supplements

In 2005, 31 percent of older adults in the study were using at least five prescription medications at the same time. Six years later more than 35 percent of older adults were taking at least five prescriptions simultaneously.

More than two-thirds of the older adults using at least five prescription medications at the same time took them in addition to over-the-counter medications or dietary supplements. 

Pezalla urged people to be careful when combining supplements with prescription medicine because it can interfere with the breakdown of a medication, and vice-versa.

“Supplements can interact with other medications and usually the interactions are harder to predict,” Pezalla said. “You either end up with too much or too little of something because you can’t break it down.”

John Moore, DO, FAAFP, Aetna’s medical director for the Northeast Region, added that herbal supplements can cause havoc in the body if they are taken with certain medication. Researchers have compared the 20 most commonly used prescriptions and 20 most popular supplements and found 93 potentially dangerous drug interactions.

For example, the FDA warns that serious drug interactions can occur if St. John’s wort, a supplement often used for depression, is mixed with a variety of medications including drugs for HIV/AIDS, heart disease, and medications for patients who have undergone an organ transplant.  In addition, St. John’s wort is known to reduce the effectiveness of antidepressants and birth control pills.

 The FDA also warns that ginkgo biloba, an herbal supplement that is supposed to help memory and improve circulation, can lead to a higher risk of internal bleeding and hemorrhagic stroke when mixed with common medications for thinning of the blood such as warfarin, clopidogrel, aspirin and other prescription blood thinners. Ginkgo biloba is also known to reduce the potency of seizure medications.  

Experts offer help

The American Geriatric Society put together the Beers List, which contains numerous medications older adults should avoid. Aetna also offers its members access to Rx Check, which is a tool that looks for interactions between drugs. It also alerts physicians to serious drug interactions. If you’re not an Aetna member, CVS offers an online tool to check drug interactions.

It’s important to disclose information about what kinds of supplements are being taken to a health care professional, Pezalla said. If you’re thinking about using a supplement, but are taking other medication, don’t be afraid to ask if it’s safe.

“Some people mistakenly believe if a medication, vitamin or supplement is available without a prescription, they must be less powerful than drugs that are only available with a prescription,” he said. “In reality, anything you take may interact with anything else you ingest.”