Efficacy of long-term antimicrobial prophylaxis after acute pyelonephritis in pregnancy.

The efficacy of antimicrobial prophylaxis for recurrent urinary infection after an episode of acute febrile pyelonephritis was assessed in 27 pregnant women. Immediately following a 2-week treatment course for acute pyelonephritis, low-dose prophylaxis with a proper antimicrobial agent taken at bedtime daily was continued until 1 month after delivery. 23 women received 50 mg of nitrofurantoin, and 2 each were given 250 mg of amoxycillin and 250 mg of cephalexin, respectively. The treatment regimens were well tolerated and there were no breakthrough infections during a total of 7.8 patient-years of treatment. These results show that long-term low-dose antimicrobial prophylaxis is highly effective in this population at high risk of recurrent acute pyelonephritis.