Non-pregnant women who have had several urinary tract infections are less likely to have another infection if they take antibiotics for six to 12 months

Urinary tract infections (UTI) are infections of the bladder and kidneys. They can cause vomiting, fever and tiredness, and occasionally kidney damage. The review found that non-pregnant women who had two or more UTIs in the past year had less chance of having a further UTI if given a six to 12 month treatment with antibiotics. The most commonly reported side effects are digestive problems, skin rash and vaginal irritation. More research is needed determine the optimal duration for antibiotic treatment.

Authors' conclusions: 

Continuous antibiotic prophylaxis for 6-12 months reduced the rate of UTI during prophylaxis when compared to placebo. After prophylaxis two studies showed no difference between groups. There were more adverse events in the antibiotic group. One RCT compared postcoital versus continuous daily ciprofloxacin and found no significant difference in rates of UTIs, suggesting that postcoital treatment could be offered to woman who have UTI associated with sexual intercourse.

Read the full abstract...

Urinary tract infection (UTI) is a common health care problem. Recurrent UTI (RUTI) in healthy non-pregnant women is defined as three or more episodes of UTI during a twelve month period. Long-term antibiotics have been proposed as a prevention strategy for RUTI.


To determine the efficacy (during and after) and safety of prophylactic antibiotics used to prevent uncomplicated RUTI in adult non-pregnant women.

Search strategy: 

We searched MEDLINE (from 1966), EMBASE (from 1980), Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and reference lists of retrieved articles.

Selection criteria: 

Any published randomised controlled trial where antibiotics were used as prophylactic therapy in RUTI.

Data collection and analysis: 

Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI).

Main results: 

Nineteen studies involving 1120 women were eligible for inclusion.
Antibiotic versus antibiotic (10 trials, 430 women): During active prophylaxis the rate range of microbiological recurrence patient-year (MRPY) was 0 to 0.9 person-year in the antibiotic group against 0.8 to 3.6 with placebo. The RR of having one microbiological recurrence (MR) was 0.21 (95% CI 0.13 to 0.34), favouring antibiotic and the NNT was 1.85. For clinical recurrences (CRPY) the RR was 0.15 (95% CI 0.08 to 0.28). The NNT was 1.85. The RR of having one MR after prophylaxis was 0.82 (95% CI 0.44 to 1.53). The RR for severe side effects was 1.58 (95% CI 0.47 to 5.28) and for other side effects the RR was 1.78 (CI 1.06 to 3.00) favouring placebo. Side effects included vaginal and oral candidiasis and gastrointestinal symptoms.

Antibiotic versus antibiotic (eight trials, 513 women): These trials were not pooled. Weekly perfloxacin was more effective than monthly. The RR for MR was 0.31(95% CI 0.19 to 0.52). There was no significant difference in MR between continuous daily and postcoital ciprofloxacin.