Purchases of cholesterol and diabetes prescription drugs by elderly Medicare beneficiaries reached nearly $19 billion in 2007, equating to about one-fourth of the approximately $82 billion spent for medications for the elderly, says the federal Agency for Healthcare Research and Quality (AHRQ).

Metabolic drugs, which are used to lower cholesterol levels, to keep diabetes under control, and to address weight and thyroid problems, topped the list of the five leading categories of drugs purchased by the elderly. The analysis by the federal agency found that the other four drug classes in the top five in 2007 were:

•Cardiovascular drugs, including blood pressure medicines, diuretics, and drugs to control abnormal heart rhythms, such as atrial fibrillation, at $15 billion.

•Central nervous system drugs, such as arthritis and other pain medications, $8 billion.

•Gastrointestinal drugs, which include antacid medications, $7 billion.

•Hormones, to treat osteoporosis, cancer, and other conditions, $5 billion.

The focus of AHRQ, which is part of the U.S. Department of Health and Human Services, is to improve the quality, safety, efficiency, and effectiveness of health care for all Americans. The data were reported in an AHRQ News and Numbers summary taken from the Medical Expenditure Panel Survey (MEPS), a detailed source of information on the health services used by Americans, the frequency with which they are used, the cost of those services, and how they are paid.