Trimethoprim-sulphadiazine prophylaxis in children with vesico-ureteric reflux.

The efficacy of long-term low-dose prophylaxis with co-trimazine (1-2 mg trimethoprim and 4.5-9 mg sulphadiazine per kg body weight) was studied in 55 children with dilated vesico-ureteric reflux. Of 44 girls, there were 13 with break-through urinary tract infection, all caused by resistant bacteria and in all but one case of pyelonephritic type. The recurrence rate was 1.5/100 treatment months. In 11 boys, there were no break-through infections in 311 treatment months. Co-trimazine was thus an effective drug for prevention of urinary tract infection in this high-risk population.