The Treatment of Urinary Tract Infections in Out-Patients. A Double-Blind Comparison between Trimethoprim and Nitrofurantoin

摘要

The rate of side-effects should today be more important for the choice of an agent for treatment of acute urinary tract infections than the cure rate, as this usually is above 90%. The side-effects with co-trimoxazole (trimethoprim-sulphamethoxazol) have been viewed as caused mainly by the sulphonamide component. In this randomized, double-blind trial Group A has been treated with trimethoprim 200 mg x 2 and Group B with nitrofurantoin 50 mg x 4 for a duration of 10 days. There was no difference in cure rate between the two groups. The rate of side-effects was 26% in Group A and 12% in Group B. In Group A 12% had skin eruptions, mostly appearing on Day 7 or later, in Group B 1.3% had eruptions. These differences are statistically significant (p < 0.05). This result, together with a survey of the literature, indicates that the frequency of these rashes might be related both to dosage and duration of treatment. The origin of the side-effects caused by co-trimoxazole should be reconsidered. The in vitro sensitivity against trimethoprim and nitrofurantoin was tested using a disc diffusion method in 98 infecting strains from patients in this study. Two per cent were resistant against trimethoprim and 81% against nitrofurantoin. We found no correlation between the size of the inhibition zone and bacteriological cure rate. This makes the value of the disc diffusion method in out-patients with acute urinary tract infections questionable.