What medication is used to treat painful or burning urination due to a urinary tract infection (UTI)?

Treatment for Painful/Burning Urination in UTIs

For painful or burning urination due to urinary tract infection (UTI), nitrofurantoin 100mg twice daily for 5 days is the first-line treatment option for uncomplicated UTIs if the patient has normal renal function (GFR >30 mL/min). 1

First-Line Treatment Options

Nitrofurantoin

• Recommended by the World Health Organization as a first-choice antibiotic for lower UTIs 1
• Dosage: 100mg twice daily for 5 days
• Advantages:
  • Excellent efficacy against E. coli (which causes 75-95% of uncomplicated UTIs)
  • Lower risk of resistance development
  • High urinary concentrations
  • Spares use of more systemically active agents
• Contraindication: Should not be used if creatinine clearance is less than 30 mL/min 1

Alternative First-Line Option

• Trimethoprim-sulfamethoxazole (TMP-SMX)
  • Dosage: 160/800mg twice daily for 3 days
  • Only recommended if susceptibility is confirmed due to increasing resistance rates 1, 2
  • FDA-approved for UTI treatment with dosing of one double-strength tablet every 12 hours for 10-14 days 2

Second-Line Options

Fosfomycin

• Dosage: 3g single dose
• Good option for uncomplicated UTIs 1
• Comparable efficacy to nitrofurantoin but with higher incidence of adverse events 3

Other Alternatives (for complicated or resistant infections)

• Fluoroquinolones (e.g., ciprofloxacin 400mg twice daily)
  • Less reliable due to increasing resistance 1
• Beta-lactams (cefuroxime, etc.)
  • Less effective for uncomplicated UTIs and associated with more adverse effects 1

Treatment Duration

• Uncomplicated UTIs: 3-5 days
• Complicated UTIs: 7-10 days
• Pyelonephritis: 10-14 days 1

Special Considerations

Renal Function

• For patients with impaired renal function (GFR <30 mL/min), nitrofurantoin is contraindicated
• TMP-SMX requires dose adjustment based on creatinine clearance:
  • CrCl >30 mL/min: Standard regimen
  • CrCl 15-30 mL/min: Half the usual regimen
  • CrCl <15 mL/min: Not recommended 2

Elderly Patients

• Avoid treating asymptomatic bacteriuria in elderly patients as this does not improve outcomes and contributes to antibiotic resistance 1

Prevention of Recurrent UTIs

For patients with recurrent UTIs, consider preventive strategies:

1. Non-antimicrobial approaches:

   • Increased water intake (additional 1.5L daily) 4
   • Cranberry products containing 36mg proanthocyanidin 4
   • Vaginal estrogen for postmenopausal women 4, 1

2. Antimicrobial prophylaxis (if other measures fail):

   • TMP-SMX: 40mg/200mg once daily or three times weekly
   • Nitrofurantoin: 50mg or 100mg daily 4
   • Methenamine hippurate: 1g twice daily 4

Common Pitfalls to Avoid

1. Treating asymptomatic bacteriuria unnecessarily
2. Using broad-spectrum antibiotics for uncomplicated UTIs
3. Not considering renal function when selecting antimicrobials
4. Inadequate treatment duration leading to recurrence
5. Not obtaining urine culture before starting therapy in complicated cases or recurrent infections

Remember that confirmation of diagnosis with urine culture is important before initiating therapy, especially in complicated cases, though empiric therapy may be started while awaiting results in symptomatic patients.