Polypharmacy and Deprescribing in Older Adults: A Preventive Medicine Approach to Optimizing Medication Use and Reducing Adverse Events

Abstract Polypharmacy, typically defined as the concurrent use of five or more medications, affects 30%–50% of community-dwelling older adults and over 90% of nursing home residents. Excessive polypharmacy (defined as the use of 10 or more medications concurrently) affects approximately 30%–45% of older adults in various settings. While medications provide essential therapeutic benefits, polypharmacy increases the risks of adverse drug events, drug–drug interactions, medication nonadherence, cognitive impairment, falls, hospitalizations, and mortality. The ageing population's increasing prevalence of multimorbidity drives inappropriate polypharmacy, yet many prescribed medications lack evidence of benefit in older adults or may cause more harm than good. Deprescribing, the systematic process of tapering or stopping medications when potential harms outweigh benefits, represents a crucial preventive medicine strategy to optimise therapeutic regimens and reduce medication-related morbidity. This narrative review examines the epidemiology and consequences of polypharmacy, identifies medication classes particularly problematic in older adults, and synthesises evidence on deprescribing interventions and their outcomes. We explore systematic approaches to medication review, including the screening tool of older persons' prescription/screening tool to alert to right treatment criteria, Beers Criteria, and Medication Appropriateness Index. Barriers to deprescribing from patient, prescriber, and health system perspectives are discussed alongside strategies to overcome resistance and implement sustainable deprescribing programs. Legal and medicolegal implications of deprescribing are addressed to guide safe clinical practice. Evidence from recent randomised trials demonstrates that systematic deprescribing reduces medication burden without compromising health outcomes and may improve quality of life, cognitive function, and reduce healthcare utilization. This review provides practical frameworks for identifying deprescribing opportunities and implementing patient-centred medication optimization in diverse clinical settings.