[Epidemiology and therapy of bacterial infections in geriatrics]

As the elderly segment of our population expands, there is an increase of therapeutic problems considering this age group. The elderly patient is generally susceptible to infections because of the decline in host defense mechanisms that occurs with aging, and the underlying chronic diseases of these patients. Increasing numbers of elderly people are being treated in hospitals and are additionally at particular risk of acquiring nosocomial infections with antibiotic-resistant organisms. This article focuses on the epidemiological considerations, risk factors, types of infections that occur in elderly patients, and the guidelines for empiric therapy. The most common infections of the elderly are respiratory tract infection, urinary tract infection, and skin and soft tissue infection. Empirical therapy should be broader in spectrum for elderly patients since the variety of infecting bacteria tends to be greater and the choice of antimicrobial therapy must be based on risk stratification (age, medical illnesses, and severity of presentation). Many additional aspects, e.g., route of administration, drug pharmacokinetics and pharmacodynamics, drug toxicity and drug-drug interactions, compliance, and multiple underlying diseases (e.g., renal failure) must be considered in the rational selection of antibiotic regimen.