Abstract
Pneumonia is a common cause of death in older people. Antimicrobial drugs do not prevent pneumonia and, because of increasingly resistant organisms, their value in curing infection might become even more limited. Establishing new strategies to prevent pneumonia through consideration of the mechanisms of this devastating illness is essential. The purpose of this review is to discuss how pneumonia develops in the elderly and to suggest preventive strategies that may reduce the incidence of pneumonia among them. Aspiration of oropharyngeal bacterial pathogens into the lower respiratory tract is one of the most important risk factors for pneumonia; impairments in swallowing and the cough reflex among older adults (e.g., related to cerebrovascular disease) increase the risk for the development of pneumonia. Thus, strategies to reduce the volume and pathogenicity of aspirated material should be pursued. For example, since both swallowing and the cough reflex are mediated by the endogenous substance P, pharmacologic therapy using angiotensin converting enzyme inhibitors, which decrease substance P catabolism, may improve both reflexes and result in a lowering of the risk of pneumonia. Similarly, since the production of substance P is regulated by dopaminergic neurons in the cerebral basal ganglia, treatment with dopamine analogs or potentiating drugs such as amantadine (and, of course, prevention of cerebral vascular disease, which can result in basal ganglia strokes) could also affect the incidence of pneumonia. Thus, promising pharmacologic treatments for preventing pneumonia in the elderly and other proven strategies, e.g., infection control and cerebrovascular disease prevention, might lessen the incidence of pneumonia.
