Aging is associated with a decreased physiological functioning, reflec
ting the body's progressive inability to maintain homeostasis as age i
ncreases. The physiological dysfunctions experienced in response to th
e aging process increases the individual's susceptibility to infection
. Indwelling catheters and other attending procedures may provide a mi
croenvironment conducive to infection. Urinary infections in the elder
ly are more commonly asymptomatic; treatment for asymptomatic bacteriu
ria is not justified and will often present opportunities for the orga
nism to acquire antimicrobial resistance. Antimicrobial selection for
the treatment of complicating symptomatic urinary infections in elderl
y subjects is complicated by the many physiological and environmental
conditions associated with older age patients.