Duration of antibiotic treatment for acute pyelonephritis and septic urinary tract infection-7 days or less versus longer treatment: systematic review and meta-analysis of randomized controlled trials

Background: Acute pyelonephritis is a frequent cause of morbidity, with a wide variation in duration of therapy. We performed a systematic review of all randomized controlled trials (RCTs) comparing <= 7 days treatment with a longer course. Methods: Electronic databases were searched to identify RCTs that assessed adults treated for pyelonephritis, comparing a 7 day or shorter versus longer therapy. Primary outcome was clinical failure at the end of the long treatment arm (EOT). Secondary outcomes included clinical failure at the end of follow-up (EOF), microbiological failure, all-cause mortality, the development of resistance and adverse events. Results: Clinical failure at EOT did not significantly differ between the two treatment arms [relative risk (RR) 0.63, 95% CI 0.33-1.18, I-2 = 41%]. Results did not differ when including studies comparing only fluoroquinolones, reducing the heterogeneity (RR 0.76, 95% CI 0.49-1.17, I-2 = 0%). We found no difference between the short and long treatment arms regarding clinical failure at EOF, even in a small subgroup of bacteraemic patients. No difference was found between the arms regarding microbiological failure at EOF, except in a subgroup of studies with a high percentage of patients with urogenital abnormalities, where microbiological failure at EOF was significantly higher in the short treatment arm (RR 1.78, 95% CI 1.02-3.10, I-2 = 21%). Adverse events were similar between the arms. Conclusions: Seven days of treatment for acute pyelonephritis is equivalent to longer treatment in terms of clinical failure and microbiological failure, including in bacteraemic patients. In patients with urogenital abnormalities, the evidence, although weak, suggests that longer treatment is required.