New Study Shows Dangers of Mixing OTC Drugs and Prescriptions Prevalence

Many older Americans are placing themselves at risk every day without even being aware that swallowing that over-the-counter medication or herbal extract, along with the medication prescribed by their doctor could have dire consequences when the drugs interact. So says a study by researchers at the University of Chicago Medical Center released in the Journal of the American Medical Association on December 24.

The study involved over 3,000 individuals aged 57 to 85, and showed that over 4% of those surveyed (about 2.2 million people nationwide) are placing themselves at significant risk of major drug interactions when they mix over the counter (OTC) drugs and dietary supplements with prescription medications, especially when it comes to anti-coagulants commonly prescribed for patients with cardiovascular disorders.

Data for the study was collected for the National Social Life, Health and Aging Project in 2005 and 2006, and involved in-home interviews of a cross-section of Americans, and checking medication logs kept by the respondents.

"We find that they commonly combine these prescription medications with over-the-counter medications and dietary supplements, which can increase their vulnerability to medication side-effects and drug-drug interactions," said Stacy Tessler Lindau MD, one of the study's authors. Tessler Lindau is an assistant professor at the University of Chicago Medical Center.

One surprising result of the survey - nearly 91% of those surveyed take a prescription medication every day, and nearly a third (29%) are taking five or more prescription medications daily. The number of daily medications tracks with the age of the patient, increasing as they grow older.

Tessler Lindau was partially reassured by some of the results, noting that "...we did not find combinations of the most commonly used drugs that were absolutely forbidden, one indication that drug safety systems used by physicians, nurses and pharmacists are working."

"However," she added, "our results probably underestimate total risk." This is because some patients take more esoteric and less-commonly used medications and combine them with herbal extracts, in which the interaction between the medications is not as well documented, or even been studied.

The study shows that 68% of those people who take a prescribed medication also take an over the counter medication - many times without advising or consulting with their physician or pharmacist on potential interactions. This puts health care professionals at a significant disadvantage when trying to assess the dangers of drug interactions when creating a profile of their patients.

The conclusion - before taking any over the counter medication, dietary supplement, or herbal extract, check with your physician and/or pharmacist for a potentially dangerous - or fatal - interaction.