Antibiotics for Asymptomatic Bacteriuria

Summary

A Cochrane review [Abstract] 1 included 9 studies with a total of 1614 subjects. The effectiveness and safety of antibiotics treatment for asymptomatic bacteriuria was assessed in adults of different age, mainly elderly. Treatment varied including nitrofurantoin, trimethoprim, sulpha-trimethoprim, fluoroquinolones, amoxicillin, cefaclor etc. Symptomatic urinary tract infection (UTI) (RR 1.11, 95% CI 0.51 to 2.43; 5 trials, n=1046), complications (RR 0.78, 95% CI 0. 35 to 1.74; 3 trials, n=814), and death (RR 0.99, 95% CI 0.70 to 1.41; 6 trials, n=761) were similar between the antibiotic and placebo or no treatment arms. Antibiotics were more effective for bacteriological cure (RR 2.67, 95% CI 1.85 to 3.85; 9 trials, n=1154) but also more adverse events developed in this group (RR 3.77, 95% CI 1.40 to 10.15; 4 trials, n=921). No decline in the kidney function was observed across the studies; minimal data were available on the emergence of resistant strains after antimicrobial treatment.

A meta-analysis 2 included 50 studies involving 7088 patients. Overall, quality of evidence ranged from very low to low. There was no evidence of benefit for patients with no risk factors, patients with diabetes mellitus, postmenopausal women, elderly institutionalised patients, patients with renal transplants, or patients prior to joint replacement, and treatment was harmful for patients with recurrent urinary tract infection (UTI). Treatment of ABU resulted in a lower risk of postoperative UTI after transurethral resection surgery. In pregnant women, we found evidence that treatment of ABU decreased risk of symptomatic UTI, low birthweight, and preterm delivery.