Prescription Drugs and Drug Interactions
Prescription Drug Abuse and Misuse in the Elderly
Thomas L. Patterson, Ph.D.
Approximately 12 percent of U.S. health expenditures are dedicated to prescription drugs. This amount is steadily increasing, reported Dr. Thomas Patterson, and the greatest expenditures are among the elderly. Approximately 30 percent of prescriptions are consumed by those over age 65.
The elderly spend as much as $15 billion each year on prescriptions, which is four times the spending level of younger individuals. The greater use of prescription medications by the elderly is largely due to increased medical conditions with age. However, prescription drug misuse also occurs in this population. There are a number of types of misuse, including overdose, underdose, use of prescriptions for reasons other than prescribed, and drug combinations that may poorly interact. Reasons for misuse of medications include difficulties in reading and following prescriptions, cognitive deficits, cost of meds, and complexity of drug treatment. The largest proportion of medications taken by the elderly target cardiovascular, central nervous system, and musculoskeletal problems. The
most frequently abused drugs by the elderly are opiates. Prevalence estimates of abuse by the elderly may be conservative due to problems with definitions and diagnoses of drug abuse among this age group. Age-associated changes in pharmacokinetics and the impact of psychosocial factors may have unique impacts on the onset and exacerbation of drug problems as they relate to the prevalence of drug problems among aging Americans.
Dr. Patterson suggested goals and strategies for the field, such as improving diagnostic criteria, focusing research on compliance, standardizing prescription labeling, developing treatment programs tailored to elderly, considering dual diagnosis (e.g., posttraumatic stress disorder and drug use), explicating age-related changes in drug abuse, examining ethnic and cultural differences, and examining the impact of Internet/foreign purchase of medications.
Prescription Drug Nonmedical Use and Abuse in Older Women
Linda Simoni-Wastila, Ph.D.
The use, nonmedical use, and abuse of prescription drugs with addiction potential is a current and growing problem among today’s older adults. Although the true extent of prescription drug abuse and dependence in older adults remains unknown, in 1999, nearly 7.2 million older adults were medically exposed to prescription drugs with addictive potential. Further, it is widely acknowledged that nonmedical prescription drug use and abuse will be compounded in the near future as the baby boomer population, known for both its historical and current acceptance of licit and illicit drug taking, begins entering older adulthood. Indeed, of all individuals in treatment for substance abuse disorder, it is estimated that nearly half belongs to this aging cohort. Although little research has been conducted on factors associated with nonmedical prescription drug use and abuse in older adults, the female gender has emerged as one of its most significant immutable predictors.
This finding stands in sharp contrast to the tremendous body of literature that finds the male gender a robust factor for use of other substances, including alcohol and illicit drugs. This presentation aimed to document the prevalence of prescription drug nonmedical use and abuse in older men and women, and examine the risk and protective factors common to both genders, as well as those that may be specific to gender. The discussion concluded with some observations concerning the growing problem of nonmedical prescription drug use and abuse, and the ramifications for prevention and treatment efforts aimed at elderly and near-elderly men and women.
Drug Interactions in Older Adults
Joseph T. Hanlon, Pharm.D.
Dr. Joseph T. Hanlon presented drug-drug interactions involving both pharmacokinetic and pharmacodynamic mechanisms. Specifically, he focused on those drug interactions involving narrow therapeutic-range drugs and those that are clinically significant. Herb-drug interactions and others involving food and drink (including grapefruit juice) also were briefly discussed. In addition, Dr. Hanlon presented data from his new research focusing on drug-disease interactions in older adults. The presentation concluded with a discussion on the epidemiology of drug interactions in older adults and strategies to prevent or manage drug interactions.