What can be given to a patient with suspected urinary tract infection who is not currently on antibiotics?

Treatment for Suspected Urinary Tract Infection

For patients with suspected urinary tract infection who are not currently on antibiotics, empiric antibiotic therapy should be initiated with nitrofurantoin, fosfomycin trometamol, or trimethoprim-sulfamethoxazole based on local antimicrobial sensitivity patterns. 1, 2

First-Line Treatment Options

• Nitrofurantoin macrocrystals: 50-100 mg four times daily for 5 days or nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days 2
• Fosfomycin trometamol: 3 g single dose 2, 1
• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days (not in last trimester of pregnancy) 2, 3
• Pivmecillinam: 400 mg three times daily for 3-5 days (if available) 2, 1

Diagnostic Approach

• Obtain urinalysis and urine culture before starting antibiotics to confirm diagnosis and guide therapy 2
• Do not treat asymptomatic bacteriuria except in pregnancy or before urological procedures 2
• For patients with systemic symptoms (fever, flank pain), consider blood cultures to rule out upper UTI or urosepsis 2

Treatment Considerations

• Base antibiotic selection on:

  • Local antimicrobial resistance patterns 2, 1
  • Patient allergies and comorbidities 3
  • Pregnancy status (avoid trimethoprim in first trimester) 2
  • Renal function (adjust dosing for impaired renal function) 4, 3

• For men with suspected UTI, use longer treatment duration (7 days) 2

Special Populations

• Pregnant women: Screen for and treat asymptomatic bacteriuria with standard short-course treatment or single-dose fosfomycin trometamol 2
• Patients with recurrent UTIs: Consider prophylactic antibiotics after discussing risks and benefits 2, 5
• Patients with renal insufficiency: Avoid nitrofurantoin if creatinine clearance <30 mL/min 3, 1
• Immunocompromised patients: Consider broader spectrum coverage and longer duration 2

Second-Line Options

• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) if local E. coli resistance is <20% 2, 1
• Amoxicillin-clavulanate: 20-40 mg/kg per day in 3 doses 2, 1
• Fluoroquinolones (e.g., ciprofloxacin): Reserve for complicated UTIs due to increasing resistance and adverse effects 4, 1

Common Pitfalls to Avoid

• Do not use antibiotics for asymptomatic bacteriuria except in pregnancy or before urological procedures 2
• Avoid fluoroquinolones as first-line therapy due to increasing resistance and risk of adverse effects including tendinopathy 4, 1
• Ensure adequate hydration during treatment to prevent crystalluria, especially with ciprofloxacin 4
• Do not use nitrofurantoin for suspected pyelonephritis or systemic infection as it does not achieve therapeutic blood levels 2, 1
• Avoid unnecessary prolonged courses of antibiotics; 3-5 days is sufficient for uncomplicated cystitis in women 2, 6

Follow-up

• Routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 2
• For patients whose symptoms do not resolve by the end of treatment or recur within 2 weeks, obtain urine culture and antimicrobial susceptibility testing 2
• Consider urological evaluation for patients with recurrent UTIs to identify underlying anatomical or functional abnormalities 2