Summary: The inappropriate use of prescription drugs is particularly hazardous for the elderly. Not only do they use more prescription drugs than any other age group, the elderly are more likely to take several drugs at once, increasing the likelihood of harmful drug reactions. Furthermore, the elderly do not eliminate drugs from their systems as efficiently as younger patients because of decreased liver and kidney function. GAO found that 17.5 percent of nearly 30 million noninstitutionalized Medicare recipients age 65 or older used at least one drug identified as generally unsuitable for elderly patients since safer alternative drugs exist. Inappropriate prescription drug use can result from doctors using outdated prescribing practices, pharmacists not doing drug utilization reviews, and patients not telling their doctors and pharmacists about all the drugs they are taking. Recent initiatives are seeking to address this problem. Federal and state efforts have encouraged the development and dissemination of detailed information on the effect of prescription drugs on the elderly, and the medical community is urging doctors to increase their knowledge of geriatrics and elderly clinical pharmacology. At the same time, drug utilization review systems now allow prescriptions to be screened before they are filled to identify potential problems, such as adverse drug interactions or inappropriate dosage levels. Changes in the health care delivery system may also help reduce inappropriate use of prescription drugs. For example, managed care plans, through the use of controls such as a "gatekeepers," could potentially improve the coordination of drug therapies for newly enrolled elderly patients.