Comparison of three- and ten-day regimens with a sulfadiazine-trimethoprim combination and pivmecillinam in acute lower urinary tract infections.

132 female hospital employees (mean age 32 years) with uncomplicated, bacteriologically verified acute lower urinary tract infection were included in a randomized study. The patients were treated for 3 or 10 days with a sulfadiazine-trimethoprim combination (500 mg + 150 mg) b.i.d. or for 3 or 10 days with pivmecillinam (500 mg) t.i.d. The first follow-up evaluation was performed 3-5 days after the treatment. In both sulfadiazine-trimethoprim groups the cure rate was 97% and in both pivmecillinam groups 80%. This difference was mainly due to the occurrence of pivmecillinam-resistant Staphylococcus saprophyticus strains. 109 patients attended the second follow-up visit about 4 weeks after treatment. The prevalences of reinfections and relapses were 18% in both 3-day regimens and 4-7% in both 10-day regimens. No side-effects were reported in the 3-day sulfadiazine-trimethoprim group, while about 20% in the corresponding 10-day group had side-effects. Side-effects were not common in patients treated with pivmecillinam.