Prescription Medications Working Against Each Other

A new study finds that about 20% of older Americans with multiple chronic health conditions are being treated with drugs that work at odds with each other.

Researchers from Oregon State University and the Yale University School of Medicine conducted a study of 5,815 community-living adults between the years 2007 and 2009, in an effort to identify some of the most common competing chronic conditions in which medications for one condition may exacerbate the other. The study encompassed a nationally representative sample of older adults, both men and women. Investigators included hypertension and osteoarthritis, hypertension and diabetes, hypertension and chronic obstructive pulmonary disease, diabetes and coronary artery disease, and hypertension and depression.
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The study, which the authors note is among the first to examine the prevalence of this issue, found that 22.6% of participants received at least one medication that could worsen an existing condition. In cases where this “therapeutic competition” existed, the researchers found that it changed drug treatments in only 16% of the cases. In the remaining cases, competing drugs were still prescribed.

“This is an important finding, because over 9 million older adults in the United States as well as millions of older adults outside the U.S. may unknowingly be prescribed medications that may be causing harm,” says Jonathan Lorgunpai, a medical student at Yale University School of Medicine, and study co-author.

“This finding suggests that identifying the net benefits and harms of medications prescribed for individuals with common combinations of chronic conditions should be a research priority,” says Lorgunpai. “In the meantime, older adults and their clinicians should carefully weigh the likely benefits as well as harms of each medication, not just on the condition for which a medication is indicated, but also on coexisting conditions and on overall health.”

Direct competition between medications is just one concern for this patient group, according to the researchers. The authors note that use of multiple medications can also lead to increased numbers of falls and delirium, dizziness, fatigue, and anorexia, adding that the presence of competing medications does not necessarily contraindicate the use of necessary medications, but rather the need for this competition to be more seriously considered in treatment. 

Given the large number of older adults with multiple medical conditions and multiple prescriptions, “it’s important to consider the whole patient” when prescribing medications for these patients, says David S.H. Lee, PharmD, PhD, an assistant professor in the department of pharmacy practice at Oregon State University, and a co-author of the study.

“Because guidelines tend to focus on a single disease—and [how] to optimally treat that single disease—we’ve got to be aware of how medications treatment might affect another disease,” says Lee. “[And physicians must ask], Which medications might cause some harm that could be burdensome for this patient?”

—Mark McGraw

Reference

Lorgunpai S, Grammas M, et al. Potential Therapeutic Competition in Community-Living Older Adults in the U.S.: Use of Medications That May Adversely Affect a Coexisting Condition. PLOS One. 2014.