Treatment of pneumonia in the elderly: pharmacological considerations.

Aging is associated with a number of physiological changes, including alterations in body mass, changes in organ blood flow, and reductions in renal function. The use of any drug in an older patient requires a knowledge of the effect of these physiological changes on the pharmacokinetics of that drug. Drugs with high renal clearance, such as penicillins and aminoglycosides, have a longer half-life in elderly patients. Erythromycin and ciprofloxacin, antibiotics that use both hepatic and renal clearance, require little or no dosage adjustment when used in older patients. Side effects and drug interactions occur much more commonly in older individuals and those antibiotics used in the management of pneumonia in the elderly are reviewed in detail.