MEDICATION USE IN THE OLDER POPULATION
Although polypharmacy has been historically associated with prescription medications, any current definition of polypharmacy must also include nonprescription compounds, such as over-the-counter (OTC) products, herbal remedies, and foods or nutraceuticals. Some OTCs were formerly available by prescription, and information about potential drug interactions may be available. In contrast, relatively little reliable information is available about drug interactions associated with herbal remedies.
Memmott (2003) provides estimates of over-the-counter (OTC) medication use citing Salom and Davis (1995). Approximately 40 percent of the drugs taken by the elderly are OTC medications. Ten percent of the general population regularly uses OTC medications and 69 percent of the people over age 65 regularly use these medications. It is estimated that 15 to 20 percent of the older users do not inform their physicians of OTC use.
Bikowski, Ripsin, and Lorraine (2001) cite evidence that on average, an ambulatory older patient takes 3.4 over-the-counter medications daily. Pollow, Stoller, Forster, and Duniho (1994) reported that the most common OTC medications were analgesics and antacids.
Thirteen percent of the elderly who are regular OTC users consume alcohol and take OTC drugs concurrently (Memmott, 2003). Another 17 percent combine OTC drugs with both prescription drugs and alcohol, increasing the possibility and severity of adverse drug reactions (ADR). The risk of a serious ADR in adults age 55 to 64 is 18.5 percent; is 30.1 percent in those 75 to 84, and is 41.9 percent in those 85 and older. In a mail survey of 1,555 HMO members 65 and older, Johnson and Ried (1996) found that 18.4 percent of the sample combined a prescription drug with an OTC drug to relieve pain; 4.5 percent combined a prescription drug and an OTC drug to relieve an upset stomach; 7.1 percent combined prescription and OTC medications for cough relief; and 5.7 percent combined prescription and OTC medications to treat cold symptoms.