Urinary tract infections in patients with chronic renal insufficiency.

Despite an increasing population of patients with chronic renal insufficiency, the literature on the management of urinary tract infections (UTI) in these patients is sparse. Patients with underlying diabetes are a specific population at risk. Antimicrobial treatment of UTI requires adequate serum, renal, parenchymal, and urine concentrations of drugs with antibacterial activity versus the etiologic organism. Sulfamethoxazole and nitrofurantoin are examples of drugs with low and likely inadequate urine concentrations in patients with creatinine clearances of <50 ml/min. Urine concentrations of ciprofloxacin and levofloxacin remain sufficient as renal function fails, whereas the concentrations of gemifloxacin and moxifloxacin are too low to predict efficacy. More investigative work is needed in the management of UTI in patients with poor renal function.