Single-dose and seven-day trimethoprim and co-trimoxazole in the treatment of urinary tract infection.

One hundred and sixteen adults with symptoms of acute urinary tract infection were randomly collected into four groups and given single-dose or seven-day treatment with trimethoprim or co-trimoxazole. Of the 105 patients who completed the study, bacterial urinary infection was present in 70 patients (67 per cent). The rates for symptomatic and bacterial cures were high and indistinguishable between the groups, and there was no difference in the rate of recurrence of urinary infection in the six weeks after treatment. Side effects were lower in the group receiving single-dose trimethoprim (P=0.09).