Increasing use of medications raise risk of drug-supplement interactions: JAMA papers

By Stephen Daniells

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Related tags Food and drug administration Medicine

The increased use of multiple medications and dietary supplements among older people is potentially raising the risk for drug-supplement interactions, says a new study.

New data published in JAMA Internal Medicine​ indicates that concurrent use of at least five prescription medications increased from 30.6% in 2005-6 to 35.8% in 2010-11, while concurrent use of five or more medications or supplements of any type increased from 53.4% to 67.1%.

The study, led by Dr Dima Qato at the University of Illinois at Chicago, also found that, while the use of over-the-counter (OTC) medications declined from 44.4% to 37.9%, the use of dietary supplement use increased from 51.8% to 63.7%.

“These findings suggest that the unsafe use of multiple medications among older adults is a growing public health problem. Therefore, health care professionals should carefully consider the adverse effects of commonly used prescription and nonprescription medication combinations when treating older adults and counsel patients about these risks,”​ the authors conclude.

The article deals in predictive increases in risk and Andrea Wong, PhD, vice president, scientific and regulatory affairs for the Council for Responsible Nutrition, told us that the vast majority of these potential risk increases are for drug-drug interactions and not drug-supplement interactions. Indeed, the only supplements flagged by the researchers for drug-supplement interactions were warfarin sodium with omega-3s or garlic, or niacin with a couple of medications.

According to the authors’ calculations, the weighted prevalence estimates of potentially major interactions was 0.8% for warfarin sodium with omega-3s, and 0.0% for warfarin sodium with or garlic (compare to 1.6% for warfarin and aspirin or 4.6% for aspirin and clopidogrel bisulfate).

“The results show that the prevalence of older adults taking a combination of drugs and supplements with a potential for interaction is low, suggesting that the actual risk to consumers is low,”​ said Dr Wong.

Supplement users more likely to report CAM use

“The authors suggest that because we see an increase in the use of dietary supplements that equates to an increased risk or toxicity, and that’s not true,” ​said Dr Rick Kingston, President, Regulatory and Scientific Affairs, SafetyCall International and Clinical Professor of Pharmacy, University of Minnesota.

For more from Dr Kingston, please click HERE​. 

Another article published in JAMA Internal Medicine​ reported that many patients do not disclose to primary care physicians their use of complementary and alternative medicine (CAM).

Judy Juo and Pamela Jo Johnson of the University of Minnesota, Minneapolis, report that 42.3% of the 7,493 adults surveyed did not disclose their most used form of CAM. Yoga, tai chi or qi gong were the most common forms of CAM not disclosed, but adults who used herbs or supplements disclosed the most, said the study.

In an accompanying commentary Michael Steinman, MD, of the University of California, San Francisco, stated: “These results [from both papers] are consistent with a large body of research that has documented a seemingly inexorable rise in medication use among older adults. What they do not tell us is whether these changes are good or bad.

“This is the rub. There are many older adults who would be healthier if they threw away half of their medications. Yet, there are people with multiple chronic diseases who can benefit from multidrug therapy. The use of multiple medications indicates that a person is at higher risk of medication-related problems. It does not tell us what those problems are or what to do about them. This is particularly true when most or all of the medications can be linked to practice guidelines for the patient’s chronic diseases.

“It is time to take the next leap forward. We need to create systems that support an ongoing process of monitoring medications. Such systems would help us periodically assess the benefits, harms, and ongoing need for each of a patient’s medications, as well as the reasonableness of the medication regimen as a whole.”

Dr Wong said that CRN’s urges consumers to speak with their doctors and other healthcare practitioners about everything they consume, including dietary supplements.

Image © iStockPhoto

“Dietary supplement use is highest among older populations, according to our research, and so we support the need for techniques to enhance the transparency of what elderly patients are taking, as Dr. Steinman suggests in his commentary,” ​she said. “Creating a list of everything being taken, including dietary supplements; looking to healthcare practitioners outside of primary care physicians, such as pharmacists and nurses, as partners in health—these are practical solutions, but the onus does not lie with the patient only. Healthcare practitioners have to share the responsibility, too."

"Polypharmacy among elderly patients has always been an issue"

Dan Fabricant, PhD, Executive Director and CEO of the Natural Products Association (NPA), said that polypharmacy among elderly patients has always been an issue in medicine and is still a growing problem. "In a 7-minute doctor’s visit, rarely is there time to review a comprehensive list of medications to remove those that are no longer warranted," ​said Dr Fabricant.

"When elderly people are prescribed medications, there is no advocate for the patient to re-examine each of their medications. Physicians often rely on an oral medication history taken from a patient’s memory at a routine doctor’s visit. Generally, it isn’t until a hospital visit that a comprehensive medication reconciliation is taken that issues of polypharmacy even come up.

"NPA urges patients to discuss their comprehensive medication list with their doctor or pharmacist.  There are also many educational resources available to medical professionals, including training sessions hosted by pharmacies and pharmacy schools.”

Sources: JAMA Internal Medicine
Published online ahead of print, doi:10.1001/jamainternmed.2015.8581
“Changes in Prescription and Over-the-Counter Medication and Dietary Supplement Use Among Older Adults in the United States, 2005 vs 2011”
Authors: D.M. Qato, et al

JAMA Internal Medicine
Published online ahead of print, doi:10.1001/jamainternmed.2015.8597
“Commentary: Polypharmacy – Time to get Beyond Numbers”
Author: M.A. Steinman

JAMA Internal Medicine
Published online ahead of print, doi: 10.1001/jamainternmed.2015.8593
“Nondisclosure of Complementary and Alternative Medicine Use to Primary Care Physicians: Findings From the 2012 National Health Interview Survey”
Authors: J. Jou, P.J. Johnson

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