What are the recommended antibiotics for an uncomplicated urinary tract infection (UTI) in a patient with a penicillin allergy?

From the Guidelines

For patients with a penicillin allergy who have an uncomplicated urinary tract infection (UTI), the recommended first-line antibiotics include trimethoprim-sulfamethoxazole (TMP-SMX) 160/800 mg twice daily for 3 days, nitrofurantoin 100 mg four times daily for 5-7 days, or fosfomycin 3 grams as a single dose, as these options are effective and have low resistance rates, according to the most recent guidelines 1. The choice between these options depends on local resistance patterns, patient factors, and previous antibiotic exposure.

• TMP-SMX is often preferred due to its effectiveness, low cost, and good tissue penetration, but should be avoided if local resistance rates exceed 20% or if the patient has used it recently.
• Nitrofurantoin achieves high concentrations in urine and has low resistance rates but should not be used in patients with renal impairment (creatinine clearance <30 mL/min) or those with symptoms of upper UTI.
• Fosfomycin offers convenient single-dose treatment with good efficacy against many resistant organisms. Penicillin allergy does not typically affect these recommendations as these antibiotics belong to different classes and do not have cross-reactivity with penicillins, as noted in the guidelines 1. It's essential to consider the patient's specific situation, including any history of previous antibiotic use, renal function, and local resistance patterns, to choose the most appropriate antibiotic, as emphasized by the European Association of Urology & European Society for Paediatric Urology 1.

From the FDA Drug Label

For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris It is recommended that initial episodes of uncomplicated urinary tract infections be treated with a single effective antibacterial agent rather than the combination

The recommended antibiotic for an uncomplicated urinary tract infection (UTI) in a patient with a penicillin allergy is trimethoprim-sulfamethoxazole (PO).

• The usual adult dosage is 1 sulfamethoprim-sulfamethoxazole DS tablet every 12 hours for 10 to 14 days 2.
• Key considerations:
  • Local epidemiology and susceptibility patterns may contribute to empiric selection of therapy.
  • When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.
  • For patients with impaired renal function, a reduced dosage should be employed 2.

From the Research

Recommended Antibiotics for UTI with Penicillin Allergy

• For patients with a penicillin allergy, the recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis includes:
  • Nitrofurantoin 3, 4, 5, 6, 7
  • Fosfomycin tromethamine 3, 5
  • Pivmecillinam 3, 5
• Second-line options include:
  • Oral cephalosporins (e.g., cephalexin or cefixime) 3
  • Fluoroquinolones 3, 5
  • β-lactams (e.g., amoxicillin-clavulanate) 3, 5
• It is essential to note that the choice of antibiotic should be based on local susceptibility patterns and the patient's specific situation 3, 5

Considerations for Specific Types of UTIs

• For UTIs due to AmpC-β-lactamase-producing Enterobacteriales, treatment options include:
  • Nitrofurantoin 3
  • Fosfomycin 3
  • Pivmecillinam 3
  • Fluoroquinolones 3
  • Cefepime 3
  • Piperacillin-tazobactam 3
  • Carbapenems 3
• For UTIs due to ESBLs-E coli, treatment options include:
  • Nitrofurantoin 3
  • Fosfomycin 3
  • Pivmecillinam 3
  • Amoxicillin-clavulanate 3
  • Finafloxacin 3
  • Sitafloxacin 3

Importance of Local Susceptibility Patterns

• Knowledge of local susceptibility patterns is crucial in determining appropriate empiric antibiotic therapy for UTIs 3, 5
• The increasing prevalence of antibacterial resistance among community uropathogens affects the diagnosis and management of UTIs 5