Study: 1-in-6 older adults could be at risk for adverse drug interactions

CHICAGO — A new study published in JAMA Internal Medicine is taking a look at the potentially dangerous interactions older Americans court when taking several medications — both prescription and OTC, as well as supplements — at once. The study looked at data from the 2005-2006 and 2010-2011, comparing the two on instances of polypharmacy (concurrent use of more than five prescription medications), as well as instances of taking more than five prescription and non-prescription medicine, including OTC medication and supplements. 

 

The study found that polypharmacy instances increased among Americans 62 to 85 years old, growing from 30.6% to 35.8%, and the number of older patients taking five or more medications or supplements of any kind increased to 67.1% from 53.4%. Additionally, the study found a decline in use of OTC medications among older patients, but an increase in the concurrent use of two or more dietary supplements — from 31.6% to 47%.

 

Researchers also looked at potential interactions between the 20 most-used medications and 20 most-used supplements, finding that about 15.1% of older adults — about one-in-six — were taking medication combinations that risked major drug interactions in 2010-2011, an increase of almost double the 8.4% who were doing so in 2005-2006. The study noted especially the risks for adverse drug events among older patients taking preventative cardiovascular medications and supplements. 

 

“The use of clopidogrel in combination with omeprazole or NSAIDs is associated with an increased risk of myocardial infarction, hemorrhagic complications, or cardiovascular death,” the study says. “However, according to our analyses, approximately 1.8% of older adults (or 1 million) regularly use clopidogrel in interacting combinations.”

 

The study’s authors urge providers to take notice of the trend they’ve documented and discuss potential interactions with patients. 

 

“These findings suggest that the unsafe use of multiple medications among older adults is a growing public health problem,” the study says. “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.”