Epidemiology and antibiotic therapy for common infections in the elderly

As the elderly segment of our population expands, there is an increase of t herapeutic problems considering this age group. The elderly patient is gene rally susceptible to infections because of the decline in host defense mech anisms that occurs with aging, and the underlying chronic diseases of these patients. Increasing numbers of elderly people are being treated in hospit als and are additionally at particular risk of acquiring nosocomial infecti ons with antibiotic-resistant organisms. This article focuses on the epidem iological considerations, risk factors, types of infections that occur in e lderly patients, and the guidelines for empiric therapy. The most common in fections of the elderly are respiratory tract infection, urinary tract infe ction, and skin and soft tissue infection. Empirical therapy should be broa der in spectrum for elderly patients since the variety of infecting bacteri a tends to be greater and the choice of antimicrobial therapy must be based on risk stratification (age, medical illnesses, and severity of presentati on). Many additional aspects, e.g., route of administration, drug pharmacok inetics and pharmacodynamics, drug toxicity and drug-drug interactions, com pliance, and multiple underlying diseases (e.g., renal failure) must be con sidered in the rational selection of antibiotic regimen.