Principles of antimicrobial use in older adults.

The fundamental principles of treating infectious diseases apply to elderly patients, but certain aspects of therapy such as the selection of empiric regimens and risk stratification for severe or atypical disease are influenced by comorbidities, lifestyle, and immunosenescence. Knowledge of age-related changes in pharmacokinetic parameters and potential drug-drug interactions assists the clinician in determining appropriate dosing and monitoring parameters. Based on current evidence, the recommended approach includes careful selection and aggressive dosing of initial broad-spectrum antimicrobials followed by de-escalation to appropriate agents to maximize clinical outcomes and minimize toxicity and adverse effects. Greater enrollment of the elderly in therapeutic studies is needed to detect differences in the efficacy and safety of antimicrobials.