The results of a study published in the March 21st online-edition of  JAMA Internal Medicine, indicate that the concurrent use of interacting medications among older adults increased from 1.0% to 3.9% between 2005-2006 and 2010-2011. A salient finding of the study was that among older adult prescription medication users, concurrent use of dietary supplements increased from 53.9% to 65.7% during the same time period. According to the authors of the study, the increasing concurrent use of interacting medications and supplements may contribute to and worsen avoidable adverse drug events in older adults (Changes in Prescription and Over-the-Counter Medication and Dietary Supplement Use Among Older Adults in the United States, 2005 vs 2011).

 

See below for a summary of the study's key findings:

• Approximately 15.1%  of older adults  62 to 85 years old were using medication combinations with the potential for a major drug-drug interaction in 2010-2011.
• The use of both amlodipine and simvastatin, the most commonly used interacting drug regiment involving concurrent use of prescription medications, increased from 1.0% to 3.9%.  
• Concurrent use of aspirin with clopidogrel busulfate increased from 2.4% to 4.6%.
• The use of warfarin concurrently with omega-3 supplements, increased from .1% in 2005-2006 to .8% in 2010-2011.
• Concurrent use of  aspirin and naproxen increased from .9% to 2.2% between 2005-2006 and 2010-2011.