Stopping the effective non-fluoroquinolone antibiotics at day 7 vs continuing until day 14 in adults with acute pyelonephritis requiring hospitalization: A randomized non-inferiority trial.

Objective: To evaluate whether stopping the effective antibiotic treatment following clinical improvement at Day 7 (Truncated treatment) would be non-inferior to continued treatment until Day 14 (Continued treatment) in patients with acute pyelonephritis (APN) requiring hospitalization treated with non-fluoroquinolone (non-FQ) antibiotics.

Methods: Hospitalized adult men and non-pregnant women with culture-confirmed APN were eligible for participation after they had clinically improved following empirical or culture-guided treatment with intravenous non-FQ antibiotic(s). We excluded patients with severe sepsis, abscesses, prostatitis, recurrent or catheter-associated urinary tract infection, or urinary tract obstruction. We randomized eligible patients on Day 7 of effective treatment and assessed them at Weeks 1 and 6 after treatment completion. The primary outcome was retreatment for recurrent urinary tract infection. The prespecified non-inferiority margin was 15%.

Results: Between March 17, 2015 and August 22, 2016, we randomly allocated 54 patients-27 patients in each arm. Twenty-four (44%) patients were male, and 26 (48%) had diabetes mellitus. Escherichia coli was the most common urinary isolate (47 [87%] patients); 36 (78%) were resistant to ciprofloxacin. In all, 41 (76%) patients received amikacin-based treatment. At the end of 6 weeks, no patient in the truncated treatment arm required retreatment, whereas 1 patient in the continued treatment arm was retreated. Difference (90% CI) in retreatment was -3.7% (-15.01% to 6.15%). Upper bound of the difference (6.15%) was below the prespecified limit, establishing non-inferiority of truncated treatment. Asymptomatic bacteriuria at Week 6 was similar between the two arms (3/24 vs. 3/26; P = 1.0). Patients in the truncated treatment arm had significantly shorter hospital stay (8 [7-10] vs. 14 [14-15] days; P < 0.001) and less antibiotic consumption per patient (8.4 ± 2.8 vs. 17.4 ± 8.3 DDDs; P < 0.001).

Conclusion: Stopping the effective non-FQ antibiotics following clinical improvement at Day 7 is non-inferior to continued treatment until Day 14 in selected patients with APN requiring hospitalization.

Trial Registration: Clinical Trials Registry-India; CTRI/2016/04/006810.