Antibiotic agents in the elderly

Changes that occur in the pharmacology of drugs in the elderly must be considered in the use of antimicrobial agents. Although absorption of orally administered drugs is not affected in a significant way, renal function decreases, drug-drug interactions increase, compliance with regimens may be decreased, and drug toxicity is increased. The most frequent infections occurring in the elderly are pneumonia, urinary tract infection, and soft-tissue infection. CDAD is usually a complication of antibiotic therapy. Pneumonia can be categorized as community-acquired, LTCF, and hospital-acquired. Therapeutic approaches vary according to which of these sites is involved. Urinary tract infection is divided into upper tract infection, lower tract infection, and asymptomatic bacteriuria. Upper tract infection is treated for a longer period than lower tract infection; with few exceptions, asymptomatic bacteriuria is usually not treated. Soft-tissue infection is usually caused by an infected pressure ulcer or cellulitis (which may be a complication of a diabetic foot ulcer or an ulcer due to peripheral vascular disease). These infections have different microbial causes and require different therapeutic approaches.