(RxWiki News) If your medicine cabinet seems rather full lately, you may not be the only one.
A new study found that Americans may be significantly more medicated today than they were just 15 years ago. In fact, between 1999 and 2012, overall prescription drug use increased 8 percent among US adults.
The researchers who crunched these numbers said there is no single explanation for this striking rise in prescription drug use. However, the US "obesity crisis" may have played an important role.
According to these researchers, among the 10 drugs most widely used in 2011-2012, eight are used to treat diabetes, high cholesterol, high blood pressure and other conditions related to obesity. The ninth drug — omeprazole (brand name Prilosec) — is used to treat gastroesophageal reflux, a condition more common among obese patients.
For this study, a team of researchers led by Elizabeth D. Kantor, PhD, MPH, a professor of epidemiology at the Harvard T. H. Chan School of Public Health, used data from the 1999-2012 National Health and Nutrition Examination Survey (NHANES) to look at US trends in prescription drug use.
The NHANES included 37,959 US adults, aged 20 or older. Within each of the seven NHANES cycles included, prescription drug use in the prior 30 days was assessed.
These researchers found that the rate of prescription drug use increased from 51 percent in 1999-2000 to 59 percent in 2011-2012. The rate of polypharmacy (the use of five or more prescription drugs at one time) increased from 8 percent to 15 percent during those years.
The older the participants were, the more likely they were to use prescription drugs. For instance, 90 percent of seniors took at least one medication in 2011-2012. Thirty-nine percent took five or more. By comparison, 65 percent of middle-aged patients took at least one medication and 15 percent took five or more. The rate of prescription drug use did not increase among patients ages 20 to 39.
Dr. Kantor and team also identified 18 distinct classes of drugs that were used by at least 2.5 percent of Americans. Of those drug classes, 11 were more widely used in 2011-2012 than in 1999-2000.
The largest jump was found for hypertension (high blood pressure) drugs — from 20 to 27 percent. Medications used to treat hyperlipidemia also increased from 7 to 17 percent. Antidepressant use increased from 7 to 13 percent.
Some drug classes became less commonly used over the 12-year period, however. Chief among these were hormones used to treat women with menopausal symptoms. Their use fell from 19 to 11 percent following the discovery that hormone replacement therapy may be tied to an increased risk of breast cancer, heart disease and stroke.
The most commonly used drug in 2011-2012 was simvastatin (Zocor), a cholesterol medication.
This study was published Nov. 3 in the journal JAMA.
The National Cancer Institute and the National Institute of Diabetes and Digestive and Kidney Diseases funded this research.
Study author Dr. Andrew T. Chan disclosed consulting for the pharmaceutical companies Pfizer Inc., Bayer Healthcare and Pozen Inc.