IDSA updates guidelines for uncomplicated urinary tract infections

The Infectious Diseases Society of America updated its clinical practice guidelines for treating women with acute uncomplicated cystitis and pyelonephritis.

The guidelines apply to premenopausal, non-pregnant women with no known urological abnormalities or comorbidities. Full recommendations are online, as is an executive summary.

IDSA published its previous guidelines in 1999. Since then, antimicrobial resistance, collateral damage (defined as selection of drug-resistant organisms associated with broad-spectrum cephalosporins), newer agents and different durations of therapy have been studied. Drug-resistant courses have been included in some studies, allowing for estimations of expected response rates in real-life clinical settings.

Recommendations for acute uncomplicated cystitis are as follows:

• Nitrofurantoin monohydrate/macrocrystals (100 mg twice daily for 5 days) has minimal resistance and collateral damage, with efficacy comparable to 3 days of trimethoprim-sulfamethoxazole (good evidence from one or more randomized, controlled trials).Trimethoprim-sulfamethoxazole (160/800 mg [1 double-strength tablet] twice daily for 3 days) is appropriate if local resistance rates do not exceed 20%, or if the infecting strain is susceptible (good evidence from one or more randomized, controlled trials).Fosfomycin trometamol (3 g in a single dose) has minimal resistance and propensity for collateral damage, but it appears to have inferior efficacy compared with standard short-course regimens (good evidence from one or more randomized, controlled trials).Ofloxacin, ciprofloxacin and levofloxacin are highly efficacious in 3-day regimens but have a propensity for collateral damage and should be reserved for important uses other than acute cystitis (good evidence from one or more randomized, controlled trials). βLactam agents in 3- to 7-day regimens are appropriate when other recommended agents cannot be used (moderate evidence from one or more randomized, controlled trials). Other βlactams, such as cephalexin, are less well studied but may also be appropriate in certain settings (moderate evidence from expert consensus). βlactams generally have inferior efficacy and more adverse effects compared with other urinary tract infection antimicrobials (moderate evidence from one or more randomized, controlled trials). For these reasons, βlactams other than pivmecillinam should be used with caution for uncomplicated cystitis.Amoxicillin or ampicillin should not be used because of poor efficacy and very high antimicrobial resistance (good evidence from one or more randomized, controlled trials).

Recommendations for acute pyelonephritis are as follows:

• A urine culture and susceptibility test should always be performed, and initial empirical therapy should be tailored to the infecting uropathogen (good evidence from one or more randomized, controlled trials).Oral ciprofloxacin (500 mg twice daily) for 7 days, with or without an initial 400-mg dose of intravenous ciprofloxacin, is appropriate in patients not requiring hospitalization where the prevalence of resistance of community uropathogens to fluoroquinolones does not exceed 10% (good evidence from one or more randomized, controlled trials). If resistance exceeds 10%, an initial one-time intravenous dose of a long-acting parenteral antimicrobial, such as 1 g of ceftriaxone (moderate evidence from expert consensus) or a consolidated 24-hour dose of an aminoglycoside (moderate evidence from expert consensus), is recommended.A once-daily oral fluoroquinolone, including ciprofloxacin (1,000 mg extended release for 7 days) or levofloxacin (750 mg for 5 days), is an appropriate choice for therapy in patients not requiring hospitalization where the prevalence of resistance of community uropathogens does not exceed 10% (moderate evidence from one or more nonrandomized, case-controlled trials). If fluoroquinolone resistance exceeds 10%, an initial intravenous dose of a long-acting parenteral antimicrobial, such as 1 g of ceftriaxone (moderate evidence from expert consensus) or a consolidated 24-hour dose of an aminoglycoside, is recommended (moderate evidence from expert consensus).Oral trimethoprim-sulfamethoxazole (160/800 mg [1 double-strength tablet] twice-daily for 14 days) is appropriate if the uropathogen is known to be susceptible (good evidence from one or more randomized, controlled trials). If trimethoprim-sulfamethoxazole is used when the susceptibility is not known, an initial intravenous dose of a long-acting parenteral antimicrobial, such as 1 g of ceftriaxone (moderate evidence from one or more nonrandomized, case-controlled trials) or a consolidated 24-hour dose of an aminoglycoside (moderate evidence from expert consensus), is recommended.Oral βlactam agents are less effective than other agents (moderate evidence from expert consensus). If an oral βlactam agent is used, an initial intravenous dose of a long-acting parenteral antimicrobial, such as 1 g of ceftriaxone (moderate evidence from one or more nonrandomized, case-controlled trials) or a consolidated 24-h dose of an aminoglycoside (moderate evidence from expert consensus), is recommended.Cases requiring hospitalization should be initially treated with an intravenous antimicrobial regimen, such as a fluoroquinolone; an aminoglycoside with or without ampicillin; an extended-spectrum cephalosporin or extended-spectrum penicillin with or without an aminoglycoside; or a carbapenem. The choice among these agents should be based on local resistance data, and the regimen should be tailored on the basis of susceptibility results (moderate evidence from expert consensus).

Uncomplicated cystitis or pyelonephritis due to methicillin-resistant Staphylococcus aureus (MRSA) is uncommon, and no data support using MRSA-active agents for uncomplicated cases. Ampicillin resistance among gram-negative organisms is rising, so ampicillin accompanied by an aminoglycoside should be limited to patients in whom Enterococcus infection is suspected. Broad-spectrum antimicrobial coverage should be tailored on the basis of urine culture and susceptibility results, the guidelines said.