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.