Prevalence of prescription drug use increases substantially with age. Survey data from 2010–2011 indicate that almost 90% of older adults regularly take at least 1 prescription drug, almost 80% regularly take at least 2 prescription drugs, and 36% take at least 5 prescription drugs (1 Reference Prevalence of prescription drug use increases substantially with age. Survey data from 2010–2011 indicate that almost 90% of older adults regularly take at least 1 prescription drug, almost... read more ). When over-the-counter and dietary supplements are included, these prevalence rates increase substantially. Drug use is greatest among frail older adults, hospitalized patients, and nursing home residents.
Providing safe, effective drug therapy for older adults is challenging for many reasons:
They use more drugs than any other age group, increasing risk of adverse effects and drug interactions, and making adherence more difficult.
They are more likely to have chronic disorders that may be worsened by the drug or affect drug response.
Their physiologic reserves are generally reduced and can be further reduced by acute and chronic disorders.
Aging can alter pharmacodynamics Pharmacodynamics in Older Adults In contrast to pharmacokinetic effects, pharmacodynamics is defined as what the drug does to the body or the response of the body to the drug; it is affected by receptor binding, postreceptor... read more and pharmacokinetics Pharmacokinetics in Older Adults Pharmacokinetics is best defined as what the body does to the drug; it includes Absorption Distribution across body compartments Metabolism Excretion read more of drugs.
They may be less able to obtain or afford drugs.
There are 2 main approaches to optimizing drug therapy in older adults:
Using appropriate drugs as indicated and to maximize cost-effectiveness
Avoiding adverse drug effects by ensuring drugs are dosed correctly, discontinuing unnecessary drugs, and avoiding drug-drug and drug-disease interactions
Because the risk of adverse drug effects is higher, overprescribing (polypharmacy) has been targeted as a major problem for older adults. However, underprescribing appropriate and therapeutically beneficial drugs must also be avoided. (See also Drug-Related Problems in Older Adults Drug-Related Problems in Older Adults Drug-related problems are common in older adults and include drug ineffectiveness, adverse drug effects, overdosage, underdosage, inappropriate treatment, inadequate monitoring, nonadherence... read more and Drug Categories of Concern in Older Adults Drug Categories of Concern in Older Adults Some drug categories (eg, analgesics, anticoagulants, antihypertensives, antiparkinsonian drugs, diuretics, hypoglycemic drugs, psychoactive drugs) pose special risks for older adults. Some... read more .)
Reference
1. Qato DM, Wilder J, Schumm LP, et al: Changes in prescription and over-the-counter medication and dietary supplement use among older adults in the United States, 2005 vs 2011. JAMA Intern Med 176(4):473-82, 2016. doi: 10.1001/jamainternmed.2015.8581