The incidence of pneumonia is highest among the aged compared with other adult populations, and causes significant morbidity and mortality among this group. Most episodes of pneumonia are caused by aspiration of oropharyngeal flora into the lungs and failure of lung defence mechanisms to eliminate the aspirated bacteria.
Studies in elderly patients have shown a high rate of oropharyngeal carriage of Gram-negative bacilli and polymicrobial/mixed flora pneumonias, especially in debilitated elderly patients in nursing homes or hospitals. This information is helpful to practitioners in prescribing empirical antibiotic therapy for elderly patients with pneumonia.
Because of the many additional concerns which must be considered in the rational selection of an antibiotic regimen, e.g. route of administration, compliance, drug pharmacokinetics and pharmacodynamics, drug toxicity, and drug-disease interactions, it is also helpful for practitioners to become familiar with a small number of the large group of available antibiotics. Based on these considerations and the presumed bacteriology of pneumonia in the elderly in the 3 clinical settings (community, nursing home and hospital), a limited number of antibiotics are recommended for empirical antibiotic regimens for elderly patients with pneumonia. In particular, β-lactamase inhibitors and cotrimoxazole (trimethoprim-sulfamethoxazole) are recommended, with ciprofloxacin as an alternative agent. There is a limited role for third-generation cephalosporins and extended-spectrum penicillins. Aminoglycosides are only recommended for patients with pneumonia in the intensive care unit on mechanical ventilation. Monotherapy (single agent) should be used whenever possible.