What is the recommended treatment for acute bacterial cystitis (Urinary Tract Infection) after vaginal intercourse?

Treatment of Acute Bacterial Cystitis After Vaginal Intercourse

For acute bacterial cystitis following vaginal intercourse, first-line treatment includes fosfomycin trometamol (3g single dose), nitrofurantoin (100mg twice daily for 5 days), or pivmecillinam (400mg three times daily for 3-5 days), with post-coital prophylaxis recommended for recurrent cases. 1

First-Line Treatment Options for Acute Bacterial Cystitis

Recommended Antimicrobial Regimens

• Fosfomycin trometamol: 3g single dose 1
• Nitrofurantoin macrocrystals: 50-100mg four times daily for 5 days 1
• Nitrofurantoin monohydrate/macrocrystals: 100mg twice daily for 5 days 1
• Pivmecillinam: 400mg three times daily for 3-5 days (availability limited to some European countries) 1

Alternative Options (when first-line agents cannot be used)

• Trimethoprim: 200mg twice daily for 5 days (not in first trimester of pregnancy) 1
• Trimethoprim-sulfamethoxazole: 160/800mg twice daily for 3 days (not in last trimester of pregnancy) 1, 2
• Cephalosporins (e.g., cefadroxil): 500mg twice daily for 3 days (only if local E. coli resistance <20%) 1

Treatment Considerations

Diagnostic Approach

• Diagnosis can be made with high probability based on lower urinary tract symptoms (dysuria, frequency, urgency) and absence of vaginal discharge 1
• Urine culture is recommended when:
  • Pyelonephritis is suspected
  • Symptoms don't resolve or recur within 4 weeks after treatment
  • Women present with atypical symptoms
  • In pregnant women 1

Antimicrobial Selection Principles

• Choice should be guided by:
  • Local resistance patterns of uropathogens
  • Efficacy demonstrated in clinical studies
  • Tolerability and adverse reactions
  • Ecological effects (collateral damage)
  • Cost and availability 1
• Fluoroquinolones should be reserved for more serious infections due to potential adverse effects and collateral damage 1
• Amoxicillin or ampicillin should not be used for empirical treatment due to poor efficacy and high resistance rates 1

Management of Recurrent UTIs After Intercourse

Post-Coital Prophylaxis

• For women with UTIs associated with sexual intercourse, post-coital antibiotic prophylaxis is effective 1
• Options include:
  • Nitrofurantoin or a quinolone taken within 2 hours after sexual intercourse 1, 3
  • Trimethoprim-sulfamethoxazole taken after intercourse 4, 5

Continuous Prophylaxis (for frequent recurrences)

• Low-dose antibiotics taken at bedtime:
  • Nitrofurantoin 50mg 1
  • Trimethoprim 100mg 1
  • Norfloxacin 200mg 6
• Alternative dosing schedules that are equally effective:
  • Alternate nights
  • Three nights per week
  • After intercourse 3, 6

Important Caveats and Pitfalls

Antibiotic Stewardship Considerations

• Short-course therapy is preferred to minimize resistance development 1
• Avoid treating asymptomatic bacteriuria in patients with recurrent UTIs 1
• Fluoroquinolones should not be used as first-line therapy due to risk of serious adverse effects and increasing resistance 1
• Beta-lactams are not preferred due to collateral damage effects and tendency to promote more rapid UTI recurrence 1

Follow-up Recommendations

• Routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 1
• For women whose symptoms don't resolve by end of treatment or recur within 2 weeks:
  • Perform urine culture and antimicrobial susceptibility testing
  • Assume the infecting organism is not susceptible to the original agent
  • Consider retreatment with a 7-day regimen using another agent 1

Preventive Measures

• Increase fluid intake 1
• Regular urination 5
• Urinating after sexual intercourse 5
• Avoiding spermicides 5
• Consider cranberry juice which has modest efficacy in reducing frequency of episodes 5