The High Prevalence and Complexity of Over-the-Counter Medication Misuse in Older Adults.

Background and objectives: Older adults (≥65 years) are the largest consumers of over-the-counter (OTC) medications and exceptionally vulnerable to the risks of these medications, including adverse drug events (ADEs). However, little is known about how older adults select and use OTCs. This is the first multisite study designed to prospectively quantify the type and intended use of OTCs selected by older adults in community pharmacies where products are purchased.

Research design and methods: Older adults (n = 144) were recruited from 10 community pharmacies from a Midwestern health system. Participants were given hypothetical symptoms and asked to select one or more OTCs for self-treatment. They were asked to report how they would use the products at symptom onset and when symptoms persisted or worsened. They also reported their current medication list and health conditions. Participants' OTC selections were evaluated for 4 types of misuse: drug-age, drug-drug, drug-disease, and drug-label.

Results: Of the 144 participants, 114 (79%) demonstrated at least one type of misuse when describing how they would use their OTC selections at symptom onset. Drug-drug and drug-label misuse had the highest prevalence. Overall, 26 (18%) and 28 (19%) participants showed only drug-drug or drug-label misuse, respectively. Notably, 55 (38%) of participants demonstrated misuse in 2 or more misuse categories. Misuse potential was exacerbated when participants described treating persistent or worsening symptoms.

Discussion and implications: The results highlight the high prevalence and complexity of OTC misuse in older adults and the need for additional work to improve OTC safety.