The microbiological and pharmacokinetic profile of an antibacterial agent useful for the single-dose therapy of urinary tract infection.

Single-dose therapy of uncomplicated urinary tract infection (UTI) has been shown to be effective in many trials in adult women. The question which will be explored in this presentation is what properties constitute the ideal agent for the therapy of UTI. Important microbiological properties include spectrum of activity to include all common urinary pathogens, bactericidal action in urine and low prevalence of resistant bacteria. The vital feature of an antibacterial drug useful in the therapy of UTI is prolonged urinary concentrations. The agent must therefore be well absorbed and have slow renal excretion. Most beta-lactam drugs do not have these combined properties. Aminoglycosides are effective drugs but cannot be administered orally. Quinolones and the calcium salt of fosfomycin are useful but do not have an ideal pharmacokinetic profile. Cotrimoxazole, trimethoprim alone and the trometamol salt of fosfomycin all have good antibacterial activity combined with slow urinary excretion.