What is the first-line antibiotic for uncomplicated urinary tract infections (UTIs) in women?

From the Guidelines

The first-line antibiotics for uncomplicated urinary tract infections (UTIs) in women are nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, with specific dosing regimens including 5 days of nitrofurantoin, 3 days of TMP-SMX, or a single dose of fosfomycin. According to the most recent guidelines from the European Association of Urology 1, these medications are recommended due to their effectiveness against common UTI pathogens like E. coli. The typical regimen for nitrofurantoin is 100mg twice daily for 5 days, while TMP-SMX is usually prescribed as one double-strength tablet (160mg/800mg) twice daily for 3 days. Fosfomycin trometamol is recommended as a single 3g dose.

Key Considerations

• Local resistance patterns may influence the choice of antibiotic, with areas having high resistance rates to certain antibiotics potentially requiring alternative treatments 1.
• Fluoroquinolones are generally reserved as second-line options due to concerns about promoting antibiotic resistance and potential side effects.
• Patients should complete the full course of antibiotics even if symptoms improve quickly, drink plenty of water, and seek medical attention if symptoms worsen or don't improve within 48 hours of starting treatment.
• The American College of Physicians also recommends short-course antibiotics for uncomplicated UTIs, highlighting the importance of choosing the right antibiotic and duration of treatment to minimize resistance and side effects 1.

Treatment Options

• Nitrofurantoin: 100mg twice daily for 5 days
• Trimethoprim-sulfamethoxazole (TMP-SMX): one double-strength tablet (160mg/800mg) twice daily for 3 days
• Fosfomycin trometamol: single 3g dose
• Alternative options may include pivmecillinam or cephalosporins, depending on local resistance patterns and patient-specific factors 1.

From the Research

First-Line Antibiotics for Uncomplicated UTIs in Women

• The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females includes:
  • A 5-day course of nitrofurantoin 2, 3
  • A 3-g single dose of fosfomycin tromethamine 2, 4
  • A 5-day course of pivmecillinam 2
• High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities 2, 5

Considerations for Antibiotic Selection

• The choice of antibiotic should be based on the patient's individual risk profile, prior antibiotic treatment, spectrum of pathogens, antibiotic susceptibility, and ecological adverse effects 4
• Urine culture and susceptibility testing should be reserved for women with recurrent infection, treatment failure, history of resistant isolates, or atypical presentation 3

Alternative Treatment Options

• Second-line options include oral cephalosporins, fluoroquinolones, and β-lactams, such as amoxicillin-clavulanate 2
• Symptomatic treatment with nonsteroidal anti-inflammatory drugs and delayed antibiotics may be considered for women with uncomplicated UTIs 3