What is polypharmacy and why is it dangerous in elderly patients?

Polypharmacy is the concurrent use of five or more medications, common in elderly patients managing multiple chronic conditions. It increases the risk of adverse drug reactions, drug-drug interactions, medication non-adherence, falls, cognitive impairment, and hospitalization. Each additional medication raises the interaction risk exponentially. Medication reconciliation at every clinical encounter identifies unnecessary, duplicate, or interacting medications. The Beers Criteria list potentially inappropriate medications for older adults.