One or Three Weeks' Treatment of Acute Pyelonephritis?: A Double‐blind Comparison, Using a Fixed Combination of Pivampicillin Plus Pivmecillinam

The clinical and bacteriological effects of 1 and 3 weeks' pivampicillin plus pivmecillinam treatment were compared in a double-blind, randomized study of patients with acute pyelonephritis. Three weeks after the end of active treatment, clinical success was seen in 29 (91%) of the 32 patients on 1-week treatment, compared with 28 (97%) of the 29 patients treated for 3 weeks. Bacteriological success was seen in only nine (28%) patients in the 1-week group vs. 20 (69%) in the 3-week group (p = 0.004). This difference was mainly due to a large number of relapses of lower urinary tract infection in the 1-week group. Even in uncomplicated cases, the bacteriological result of the 1-week treatment was unsatisfactory. Side-effects were more common in the 3-week treatment group. In conclusion, 1-week treatment of patients with acute pyelonephritis is too short. Three weeks' treatment is effective in uncomplicated cases, but even longer treatment or low-dose prophylaxis is indicated in certain patients with predisposing factors.