Pharmacokinetic and pharmacodynamic aspects of antimicrobial agents for the treatment of uncomplicated urinary tract infections

Uncomplicated urinary tract infections (UTI) are treated with β-lactams, co-trimoxazole, quinolones and fosfomycin tromethamine. Due to increasing resistance of causative pathogens, antibiotics should be used by considering their pharmacodynamic and pharmacokinetic characteristics. β-lactams have time-dependent activity and should not be used once-daily. Co-trimoxazole should be restricted due to increasing chemoresistance. Fluoroquinolones play a primary role in the treatment of serious and complicated infections. Fosfomycin tromethamine is active against most urinary tract pathogens. In vitro time-kill kinetics of fosfomycin against Escherichia coli and Proteus mirabilis showed primarily concentration-dependent activity, with a prolonged post-antibiotic effect (3.4 to 4.7 h). Based on these results a single 3 g dose of fosfomycin guarantees optimal efficacy against common uropathogens with an AUC(urine)/MIC ratio of 500.