What antibiotic regimen do you order for a patient with a urinary tract infection (UTI) in the emergency department (ED)?

From the Guidelines

For a patient with a urinary tract infection in the emergency department, I typically recommend empiric treatment with nitrofurantoin 100 mg orally twice daily for 5 days for uncomplicated cystitis in women, as supported by the most recent guidelines 1. This recommendation is based on the consideration of local resistance patterns, patient allergies, pregnancy status, and renal function.

• Alternatives include trimethoprim-sulfamethoxazole (TMP-SMX) 160/800 mg (one double-strength tablet) twice daily for 3 days, or fosfomycin 3 grams as a single oral dose, as suggested by previous guidelines 1.
• For men or patients with complicated UTIs (including pyelonephritis, pregnancy, immunosuppression, or anatomical abnormalities), ciprofloxacin 500 mg orally twice daily for 7-14 days or levofloxacin 750 mg orally daily for 5-7 days may be more appropriate, as indicated by the guidelines 1.
• The choice of antibiotic should consider local resistance patterns, patient allergies, pregnancy status, and renal function, as emphasized by the guidelines 1.
• Nitrofurantoin is preferred for uncomplicated cases due to lower resistance rates and minimal impact on gut flora, as noted in the guidelines 1.
• TMP-SMX should be avoided if local E. coli resistance exceeds 20% or if the patient has used it recently, as recommended by the guidelines 1.
• Fluoroquinolones are generally reserved for complicated infections due to increasing resistance and adverse effects, as cautioned by the guidelines 1.
• Patients should be advised to complete the full course of antibiotics even if symptoms improve, drink plenty of fluids, and return if symptoms worsen or fail to improve within 48-72 hours.

From the FDA Drug Label

The recommended adult and pediatric dosages and routes of administration are outlined in the following table

Site and Type of Infection Dose Frequency Duration(days)

Mild to Moderate Uncomplicated or Complicated Urinary Tract Infections, including pyelonephritis, due to E. coli, K. pneumoniae, or P. mirabilis 0.5 to 1 g IV/IM Every 12 hours 7 to 10

Severe Uncomplicated or Complicated Urinary Tract Infections, including pyelonephritis, due to E. coli or K. pneumoniae 2 g IV Every 12 hours 10

For a patient with a urinary tract infection (UTI) in the emergency department (ED), cefepime (IV) can be ordered. The dose is:

• 0.5 to 1 g IV/IM every 12 hours for 7 to 10 days for mild to moderate uncomplicated or complicated UTIs
• 2 g IV every 12 hours for 10 days for severe uncomplicated or complicated UTIs

Alternatively, levofloxacin (PO) can be ordered. The dose is:

• 250 mg every 24 hours for 3 days for uncomplicated UTIs
• 250 mg every 24 hours for 10 days or 750 mg every 24 hours for 5 days for complicated UTIs

2, 2, 3

From the Research

Antibiotic Regimens for UTI in ED

• The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam 4.
• Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones and β-lactams, such as amoxicillin-clavulanate 4.
• For UTIs due to ESBL-producing Enterobacteriales, treatment options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 4.
• Parenteral treatment options for UTIs due to ESBL-producing Enterobacteriales include piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, and aminoglycosides including plazomicin 4.

Specific Antibiotic Options

• Levofloxacin is effective in the treatment of uncomplicated UTIs, with a 3-day course of 250 mg once daily being highly effective 5.
• Fosfomycin has been shown to be a viable option for the treatment of uncomplicated UTIs, with low resistance rates 6.
• Ciprofloxacin has been used in the treatment of UTIs, but resistance rates are increasing, and it may not be the best option in all cases 7.
• High-dose, short-course levofloxacin (750 mg for 5 days) is approved for use in the treatment of complicated UTIs and acute pyelonephritis 8.

Considerations for Antibiotic Choice

• Local susceptibility patterns and patient factors, such as recent antibiotic use, should be considered when choosing an antibiotic regimen 4.
• The potential for resistance development should be taken into account when selecting an antibiotic, and new antimicrobials should be used wisely 4.