Diclofenac Inferior to Norfloxacin for UTI, May Increase Pyelonephritis Risk

urinary tract infection
urinary tract infection
The benefit of antibiotic treatment needs to be weighed against the potential for adverse effects, at both the individual level (adverse drug reactions) and the population level (as a driver of antibiotic resistance).

Diclofenac is inferior to norfloxacin for treatment of urinary tract infection (UTI) symptoms and is likely associated with an increased risk for pyelonephritis, according to a study published in the British Medical Journal.

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) could possibly reduce antibiotic use and contribute to greater antibiotic stewardship aimed at reducing resistance. In a randomized, double blind trial (ClinicalTrials.gov identifier: NCT01039545), the effectiveness of the NSAID diclofenac was tested against the antibiotic norfloxacin for the treatment of uncomplicated UTI in women in an ambulatory setting.

A total of 125 women assigned to the diclofenac group and 118 in the norfloxacin group received treatment and 119 and 112 completed the 30-day follow in up in each group, respectively. The primary outcome, resolution of symptoms at day 3, was observed in 54% of the diclofenac group and 80% of the norfloxacin group (risk difference 27%; 95% CI, 15%-38%, one-sided P =.98 for non-inferiority, two-sided P <.001 for superiority in favor of norfloxacin group). Adverse events were more common (P =.01) and 6 cases of clinically diagnosed pyelonephritis occurred in the NSAID group.

Results showed that diclofenac is inferior to norfloxacin and could increase the risk for pyelonephritis; however, diclofenac did reduce the use of antibiotics in uncomplicated UTI. The researchers suggest that, “alternative approaches of combining symptomatic treatment with deferred, selective antibiotic use should be developed and tested in future trials.” 

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Kronenberg A, Bütikofer L, Odutayo A, et al. Symptomatic treatment of uncomplicated lower urinary tract infections in the ambulatory setting: randomised, double blind trial. BMJ. 2017;359:j4784.