The ACEP Clinical Policies Committee regularly reviews guidelines published by other organizations and professional societies. Periodically, new guidelines are identified on topics with particular relevance to the clinical practice of emergency medicine, but for which no ACEP policy is available. This article highlights treatment recommendations for acute uncomplicated cystitis in women from the Infectious Diseases Society of America (IDSA) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID).¹

If you thought the treatment of uncomplicated urinary tract infection in women was elementary emergency medicine, you may want to think again. A recent clinical guideline published jointly by IDSA and ESCMID underscores some interesting areas of physician variability in clinical practice. IDSA/ESCMID recommendations might surprise you. For example, did you know:

• That the first-line agent recommended for acute cystitis is a 5-day course of nitrofurantoin?
• That fluoroquinolones are recommended as an alternative antimicrobial regimen, to be prescribed “only when other urinary tract infection agents cannot be used”?
• That a single 3-g dose of fosfomycin is considered an alternative primary therapy for uncomplicated cystitis, and it should be used preferentially over fluoroquinolones, penicillins, and cephalosporins?

This guideline focuses specifically on the treatment of healthy women with acute, uncomplicated cystitis and pyelonephritis. Women who are pregnant, suffer from recurrent UTI, or who have known urologic abnormalities or medical comorbidities do not fit within the scope of this guideline.

Literature from 1998 to 2008 was reviewed, and 28 clinical trials and expert reviews met inclusion for analysis.

Interestingly, the authors make antibiotic stewardship (and prevention of what they call “collateral damage”) a primary objective of the guideline; in many instances, final recommendations balance medication efficacy against the threat of future drug resistance. This is a sensible approach that will help practitioners maximize the potency and longevity of our antibiotic armamentarium.

The guideline is predicated on the fact that the vast majority of uncomplicated cystitis cases are caused by Escherichia coli, with a few other species (Proteus mirabilis, Klebsiella pneumoniae, Staphylococcus saprophyticus) comprising most of the remaining cases. Local resistance patterns reported in hospital antibiograms may be skewed by frequent cultures from inpatients with complicated infections, and healthy women with acute cystitis tend to harbor more susceptible organisms with low rates of antibiotic resistance.

The first-line agent recommended in the IDSA/ESCMID guideline for acute cystitis is a 5-day course of nitrofurantoin. Randomized controlled clinical trials have demonstrated equivalent efficacy with a 7-day course of trimethoprim/sulfamethoxale (TMP/SMX) or a 3-day course of ciprofloxacin. The recommendation of this old standby drug preferentially over TMP/SMX and fluoroquinolones is based on minimal current resistance – and a low propensity for future resistance – of pathogens to nitrofurantoin.

This drug is well tolerated and has fewer side effects than the alternatives. Although TMP/SMX has long been the traditional first-line agent for acute cystitis, rising rates of resistance (especially outside the United States) prompted the IDSA/ESCMID to revise this recommendation. However, as long as local resistance patterns do not exceed 20%, TMP/SMX may be considered an alternative first-line agent.

Fosfomycin, administered as a one-time oral 3-g dose, is also classified as a first-line agent. This medication has shown equal clinical efficacy to nitrofurantoin for treatment of UTI, although in vitro bacterial clearance is lower than that of other first-line antibiotics. Fosfomycin demonstrates in vitro activity against vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum beta-lactamase (ESBL)–producing Gram-negative rods, and has minimal propensity for collateral damage. These features, in combination with the drug’s convenient single oral dose administration, make it an attractive option for treating uncomplicated cystitis.

Fluoroquinolones are highly efficacious in 3-day regimens but have a high propensity for inducing drug-resistant organisms and should be considered a second-line agent for acute uncomplicated cystitis when other UTI agents cannot be used.

Reference

1. Gupta K, Hooton TM, Naber KG, et al. Infectious Diseases Society of America, European Society for Microbiology and Infectious Diseases. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin. Infect. Dis. 2011;52:e103-e120.

Dr. Bernstein is a senior resident in emergency medicine at Yale–New Haven Hospital and is the 2011-2012 EMRA Representative to ACEP’s Clinical Policies Committee.