Polypharmacy, aging, and cancer.

The plethora of medications taken by older patients with cancer increases the risk for adverse drug reactions, drug-drug interactions, and nonadherence for this age group. Although polypharmacy can be an issue in any age group, it can especially be a problem for the elderly, who consume more medications than any other patient group. Factors such as the presence of multiple comorbid conditions, advances in pharmacotherapy, and increased availability of over-the-counter and herbal supplements for self-treatment can all contribute to polypharmacy in this population. Physiologic changes associated with aging may alter the pharmacokinetic and pharmacodynamics of drug metabolism, which, in turn, affects potential drug toxicities. The incorporation of preventive methods--such as patient and physician education, and regular medication list review and monitoring--prior to its occurrence is key to preventing polypharmacy. Clinical trials designed to better reflect the "typical" general elderly population as well as to consider the implications of cost, drug interactions/metabolism, and adherence are needed to substantiate our clinical practice when dealing with the largest subset of our cancer population.