Heavy U.S. medicine use raises concern

(CNN) -- Armed with new evidence of Americans' heavy reliance on medication, researchers warned Tuesday of the potential dangers of mixing prescription drugs or over-the-counter pain killers with unregulated herbal remedies.

The new study, published in this week's Journal of the American Medical Association, found that in any given week more than 80 percent of American adults take at least one type of medication -- from prescription drugs and over-the-counter remedies to dietary and herbal supplements. Results were based on a phone survey.

Fifty percent of the respondents took prescription drugs each week, the researchers said, and 16 percent of that group also used one or more herbal supplements. The researchers noted that other studies have found mixing herbs with prescription drugs can have adverse effects, but they did not elaborate nor did they single out any herbs that are cause for particular concern.

"Identification of usage patterns of the full range of medication, including the reasons for use, provides a basis for improving safety and reducing risks associated with their consumption," they wrote.

Doctors should ask patients about their use of herbal supplements, the report said, to help avoid interactions with other medications. Such supplements, which are not regulated by the Food and Drug Administration, are commonly available in grocery stores and pharmacies.

The researchers from the Slone Epidemiology Unit at Boston University conducted a random telephone survey of 2,590 adults over the course of nearly two years, from February 1998 through December 1999. Participants were asked about what medications they used and why they used them.

The study found that 14 percent of Americans take herbal supplements. The most popular were ginseng, ginko biloba, garlic, glucosamine and St. John's wort. Herbs like these are used to treat everything from fatigue to depression to poor circulation. They found that 81 percent of adults 18 and older used at least one medication in the preceding week. Half of all adults took a prescription drug, and 7 percent took five or more.

The most commonly used drugs were over-the-counter pain remedies such as acetaminophen, ibuprofen and aspirin.

The researchers found that women 65 and older were most likely to use medications of any kind, and men between 18 and 44 were least likely to be on medication.

Women used conjugated estrogens and thyroid drugs most often, and men used cardiovascular medicines and diuretics most often.

The researchers said the study was the first population-based survey of medication use in the United States. Typically, they said, such information is derived from drug sales figures.