Treatment of Post-Coital UTI Symptoms in Women
For a premenopausal woman with UTI symptoms after sexual intercourse, initiate low-dose post-coital antibiotic prophylaxis within 2 hours of sexual activity using nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, or trimethoprim 100 mg as a single dose. 1
Immediate Treatment of Current Symptoms
For the acute symptomatic episode, treat with first-line antibiotics:
- Fosfomycin trometamol 3 g as a single dose is the most convenient option with excellent efficacy 2
- Nitrofurantoin 100 mg twice daily for 5 days offers minimal resistance and low collateral damage to normal flora 2
- Pivmecillinam 400 mg three times daily for 3-5 days where available 2
Avoid fluoroquinolones as first-line therapy due to serious adverse effects; reserve these only for complicated infections 2. Beta-lactams like amoxicillin are inferior choices that promote rapid UTI recurrence 2.
Post-Coital Prophylaxis Strategy
The evidence strongly supports post-coital antibiotic prophylaxis for women whose UTIs are temporally related to sexual intercourse:
- Timing is critical: Take a single low-dose antibiotic within 2 hours after sexual intercourse 1
- Duration: Continue for 6-12 months 1
- Efficacy: Post-coital prophylaxis significantly reduces recurrent cystitis and is as effective as daily continuous prophylaxis 1
Preferred Antibiotic Choices for Post-Coital Prophylaxis
Select based on prior organism susceptibility, drug allergies, and antibiotic stewardship principles 1:
- Nitrofurantoin 50 mg (preferred due to low resistance) 1
- Trimethoprim-sulfamethoxazole 40/200 mg (only if local E. coli resistance <20%) 1, 2
- Trimethoprim 100 mg 1
Avoid fluoroquinolones and cephalosporins for prophylaxis to preserve antibiotic stewardship 1.
Non-Antibiotic Alternatives
If the patient prefers to avoid antibiotics or as adjunctive therapy:
- Methenamine hippurate may be effective in preventing UTIs in patients without renal tract abnormalities 1
- Lactobacillus-containing probiotics can be considered 1
- Cranberry products (minimum 36 mg proanthocyanidins daily) have modest efficacy 1, 3
Essential Behavioral Modifications
Counsel on these evidence-based lifestyle changes 1:
- Void immediately after intercourse to flush bacteria from the urethra 1
- Maintain adequate hydration throughout the day 1
- Avoid spermicides and harsh vaginal cleansers that disrupt normal vaginal flora 1
- Avoid prolonged holding of urine 1
- Avoid sequential anal and vaginal intercourse 1
- Control blood glucose if diabetic 1
Critical Pitfalls to Avoid
- Do not use prolonged antibiotic courses (>5 days) for acute treatment, as this fosters antimicrobial resistance and increases recurrence risk 1
- Do not treat asymptomatic bacteriuria between symptomatic episodes, as this increases the risk of symptomatic infection and bacterial resistance 1
- Do not use broad-spectrum antibiotics unnecessarily, as this disrupts protective periurethral and vaginal microbiota 1
- Urine culture is not routinely needed for straightforward uncomplicated cystitis unless symptoms fail to resolve, recur within 4 weeks, or the patient has atypical symptoms 2
When to Reassess
If symptoms persist despite treatment:
- Repeat urine culture before prescribing additional antibiotics 1
- Consider nitrofurantoin for re-treatment since resistance is low and decays quickly 1
- Evaluate for complicating factors: congenital urinary tract abnormalities, neurogenic bladder, immunosuppression, nephrolithiasis, or recent surgery 1
Special Consideration: Postmenopausal Women
If the patient is postmenopausal, the approach differs: