First-Line Treatment for Suspected Urinary Tract Infections
For patients with suspected urinary tract infection (UTI), first-line treatment should be nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, depending on local resistance patterns. 1, 2
Recommended First-Line Antibiotics
- Nitrofurantoin monohydrate/macrocrystals (100 mg twice daily for 5 days) is highly recommended due to minimal resistance patterns and limited collateral damage to normal flora 2
- Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days) should only be used if local resistance rates are known to be <20% or if the infecting strain is confirmed susceptible 2, 3
- Fosfomycin trometamol (3 g single dose) is appropriate for uncomplicated cystitis with minimal resistance, though it may have slightly lower efficacy compared to standard short-course regimens 1, 2
Treatment Duration
- Short-course therapy is preferred for uncomplicated UTIs to minimize side effects and resistance development 2
- Nitrofurantoin requires 5 days of treatment for optimal efficacy 2
- TMP-SMX is typically given for 3 days 2, 4
- Fosfomycin is administered as a single 3g dose 2
Diagnostic Approach
- Obtain urinalysis and urine culture with sensitivity testing prior to initiating treatment in patients with suspected UTI 1
- Microbial confirmation at the time of acute-onset urinary symptoms is important for establishing a diagnosis and guiding appropriate therapy 1
- Patient-initiated treatment (self-start) may be offered to select patients with acute episodes while awaiting urine culture results 1
Special Considerations
- Fluoroquinolones should be reserved for more serious infections due to their propensity for collateral damage and increasing resistance rates 2, 5
- Do not use ciprofloxacin and other fluoroquinolones for empirical treatment when patients have used fluoroquinolones in the last 6 months 1
- Beta-lactams should be used only when recommended first-line agents cannot be used 2
- Local resistance patterns should guide empiric therapy, particularly for TMP-SMX 2, 4
Treatment Failures
- For women whose symptoms don't resolve by the end of treatment or recur within 2 weeks, perform urine culture and antimicrobial susceptibility testing 2
- Retreatment with a 7-day regimen using a different antibiotic should be considered for treatment failures 2
Complicated UTIs
- For complicated UTIs with systemic symptoms, consider broader-spectrum antibiotics such as amoxicillin plus an aminoglycoside or a third-generation cephalosporin 1
- Treatment duration for complicated UTIs typically ranges from 7-14 days 1
Asymptomatic Bacteriuria
- Do not treat asymptomatic bacteriuria (ASB) in most patient populations 1
- Exceptions include pregnant women and patients scheduled to undergo invasive urinary tract procedures 1