From the Guidelines
Patients with a Urinary Tract Infection (UTI) who are allergic to sulfas (sulfonamides) should be treated with alternative antibiotics such as nitrofurantoin or fosfomycin.
Treatment Options
- Nitrofurantoin: a first-line agent for the treatment of UTIs, especially in patients with sulfonamide allergy, as it has a low resistance rate and is effective in treating UTIs 1.
- Fosfomycin: another first-line agent that can be used as an alternative to sulfonamides, with a low resistance rate and effective in treating UTIs 1.
- Cephalosporins: such as cefaclor, cephalexin, or cefpodoxime, can be considered as second-line agents for the treatment of UTIs in patients with sulfonamide allergy 1.
Important Considerations
- Local antibiogram: should be considered when choosing an antibiotic for the treatment of UTIs, as resistance patterns may vary geographically 1.
- Patient allergies and side effects: should be taken into account when selecting an antibiotic, and alternative agents should be chosen accordingly 1.
- Duration of treatment: should be as short as possible, generally no longer than 7 days, to minimize the risk of resistance and side effects 1.
From the Research
Treatment Options for UTI Patients Allergic to Sulfas
- For patients with a Urinary Tract Infection (UTI) who are allergic to sulfas (sulfonamides), several alternative treatment options are available 2, 3, 4, 5, 6.
- First-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females includes a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam 2, 3, 6.
- Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones, and β-lactams, such as amoxicillin-clavulanate 2.
- For UTIs due to AmpC-β-lactamase-producing Enterobacteriales, treatment options include nitrofurantoin, fosfomycin, pivmecillinam, fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems 2.
- For UTIs due to ESBLs-E coli, treatment oral options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 2.
- Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, aminoglycosides, and fosfomycin 2.
Specific Considerations
- Trimethoprim alone can be used to treat UTIs in patients who are unable to tolerate sulfonamides, but it may cause a high incidence of adverse reactions 5.
- For men with lower UTI symptoms, antibiotics should always be prescribed, with urine culture and susceptibility results guiding the antibiotic choice 6.
- First-line antibiotics for men with uncomplicated UTI include trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for seven days 6.
- Uncomplicated UTIs in nonfrail women and men 65 years and older with no relevant comorbidities necessitate a urine culture with susceptibility testing to adjust the antibiotic choice after initial empiric treatment 6.