Antibiotics versus placebo in the treatment of women with uncomplicated cystitis: a meta-analysis of randomized controlled trials

J Infect. 2009 Feb;58(2):91-102. doi: 10.1016/j.jinf.2008.12.009. Epub 2009 Feb 4.


Background: Acute uncomplicated cystitis is one of the most common bacterial infections in women and is conventionally treated with antibiotics. However, emergence of resistant uropathogens forces physicians to reconsider the prescription of antibiotics for acute uncomplicated cystitis in non-pregnant young women.

Objective: To evaluate the effectiveness of antibiotics in the treatment of acute uncomplicated cystitis.

Methods: We searched PubMed, the Cochrane Central Register of Controlled Trials and Scopus database.

Results: Five randomized controlled trials (RCTs) involving non-pregnant, non-immunocompromised adult women with clinically and microbiologically documented acute uncomplicated cystitis were included. Clinical success was significantly more likely in women treated with antibiotics versus those treated with placebo [4 RCTs, 1062 patients, random effects model (REM), odds ratio (OR)=4.81, 95% confidence intervals (CI)=2.51-9.21]. Antibiotics were also superior to placebo, regarding cure (4 RCTs, 1062 patients, REM, OR=4.67, 95%CI=2.34-9.35); microbiological eradication at the end of treatment (3 RCTs, 967 patients, REM, OR=10.67, 95%CI=2.96-38.43); after the end of treatment (3 RCTs, 738 patients, REM, OR=5.38, 95%CI=1.63-17.77), and microbiological reinfection or relapse (5 RCTs, 843 patients, REM, OR=0.27, 95%CI=0.13-0.55). However, adverse events were more likely to occur in antibiotic-treated patients versus placebo-treated women (4 RCTs, 1068 patients, REM, OR=1.64, 95%CI=1.10-2.44). No difference was found between the compared treatment arms regarding study withdrawals from adverse events, the development of pyelonephritis and emergence of resistance.

Conclusion: Antibiotics are superior to placebo regarding both clinical and microbiological success in adult non-pregnant women with microbiologically confirmed acute uncomplicated cystitis. However, they are associated with more adverse events.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Review

MeSH terms

  • Anti-Bacterial Agents / administration & dosage*
  • Bacterial Infections / drug therapy*
  • Clinical Trials as Topic
  • Cystitis / drug therapy*
  • Female
  • Humans
  • Placebos / therapeutic use*
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Placebos