Treatment of Urinary Tract Infections
Uncomplicated Cystitis in Women
For acute uncomplicated cystitis in women, first-line treatment should be nitrofurantoin (100 mg twice daily for 5 days), fosfomycin trometamol (3 g single dose), or pivmecillinam (400 mg three times daily for 3-5 days). 1
First-Line Agents
- Nitrofurantoin is highly effective with minimal resistance patterns globally and should be dosed as 100 mg twice daily for 5 days 1, 2
- Fosfomycin trometamol offers the convenience of single-dose therapy (3 g once) but may have slightly inferior efficacy compared to multi-day regimens based on FDA data 1, 2
- Pivmecillinam (400 mg three times daily for 3-5 days) demonstrates excellent activity with minimal collateral damage, though availability is limited to certain European countries 1, 2
When First-Line Agents Cannot Be Used
If the above agents are contraindicated or unavailable, consider these alternatives:
- Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days) is appropriate only if local E. coli resistance rates are below 20% and the patient has not used this antibiotic in the preceding 3-6 months 1
- Trimethoprim alone (200 mg twice daily for 5 days) can be used but avoid in first trimester pregnancy 1, 2
- Cephalosporins such as cefadroxil (500 mg twice daily for 3 days) are acceptable when local E. coli resistance is below 20% 1, 2
Agents to Avoid or Reserve
- Fluoroquinolones (ciprofloxacin, levofloxacin) are highly effective but should be reserved for more serious infections due to their propensity for collateral damage and rising resistance rates 1
- Beta-lactams (except pivmecillinam) have inferior efficacy and more adverse effects compared to other options 1
- Amoxicillin or ampicillin should never be used empirically due to poor efficacy and high global resistance rates exceeding 20% 1
Diagnostic Approach
- Diagnosis can be made clinically based on typical symptoms (dysuria, frequency, urgency) without vaginal discharge, eliminating the need for urine culture in straightforward cases 1, 2
- Reserve urine culture for suspected pyelonephritis, treatment failure, symptom recurrence within 4 weeks, atypical presentations, or pregnancy 1, 2
- Routine post-treatment cultures are unnecessary in asymptomatic patients 1
Uncomplicated Cystitis in Men
Men with lower UTI symptoms require a 7-day course of trimethoprim-sulfamethoxazole (160/800 mg twice daily) or fluoroquinolones based on local susceptibility patterns. 1, 2
- Treatment duration is longer than in women (7 days vs 3-5 days) due to anatomical differences 1, 2
- Always obtain urine culture before initiating therapy to guide antibiotic selection 3
- Consider urethritis and prostatitis as alternative diagnoses in men presenting with UTI symptoms 3
Acute Pyelonephritis
For outpatient management of acute pyelonephritis, use oral ciprofloxacin (500 mg twice daily for 7 days) only if local fluoroquinolone resistance is below 10%; if resistance exceeds 10%, give an initial dose of IV ceftriaxone (1 g) or aminoglycoside before starting oral therapy. 1
Outpatient Treatment Options
- Ciprofloxacin 500 mg twice daily for 7 days OR extended-release 1000 mg daily for 7 days 1
- Levofloxacin 750 mg daily for 5 days 1, 4
- Consider a single IV dose of ceftriaxone 1 g or consolidated 24-hour aminoglycoside dose before starting oral fluoroquinolone if resistance rates are uncertain 1
Alternative Oral Agents
- Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 14 days) only if the pathogen is known to be susceptible; if susceptibility unknown, give initial IV ceftriaxone 1 g or aminoglycoside 1
- Oral beta-lactams are less effective than other agents and require initial IV ceftriaxone 1 g or aminoglycoside, with treatment duration of 10-14 days 1
Hospitalized Patients
For women requiring hospitalization, initiate IV therapy with:
- Fluoroquinolone, OR
- Aminoglycoside with or without ampicillin, OR
- Extended-spectrum cephalosporin or penicillin with or without aminoglycoside, OR
- Carbapenem 1
Tailor therapy based on local resistance data and susceptibility results 1
Critical Resistance Thresholds
- The 10% fluoroquinolone resistance threshold for pyelonephritis is lower than the 20% threshold for cystitis, reflecting the greater severity of upper tract infections 1
- Always obtain urine culture and susceptibility testing before initiating treatment 1
Complicated UTIs
For complicated UTIs, obtain urine culture before treatment and use levofloxacin (750 mg daily for 5-10 days depending on severity) or other agents based on susceptibility results. 4
- Levofloxacin is FDA-approved for complicated UTIs at 750 mg daily for 5 days (mild-moderate) or 10 days (severe cases) 4
- Treatment selection must account for local resistance patterns, particularly for ESBL-producing organisms 5
- For ESBL-producing E. coli, oral options include nitrofurantoin, fosfomycin, pivmecillinam, or amoxicillin-clavulanate 5
- Carbapenem-resistant organisms require specialized agents such as ceftazidime-avibactam, meropenem-vaborbactam, or cefiderocol 5
Recurrent UTIs
For women with recurrent UTIs (≥3 episodes per year or ≥2 in 6 months), diagnose each episode with urine culture and consider non-antimicrobial preventive strategies before resorting to antibiotic prophylaxis. 1
Preventive Measures
- Increase fluid intake to reduce recurrence risk 1
- Vaginal estrogen replacement in postmenopausal women 2, 3
- Cranberry products and methenamine hippurate for prevention 3
- Antibiotic prophylaxis (continuous or post-coital) only after non-antimicrobial interventions fail 2
Diagnostic Workup
- Extensive workup (cystoscopy, abdominal ultrasound) is unnecessary in women under 40 without risk factors 1
- Each recurrent episode requires urine culture to guide treatment 1
Special Considerations
Treatment Failure
- If symptoms persist at treatment completion or recur within 2 weeks, obtain urine culture and susceptibility testing 1, 2
- Assume the organism is resistant to the initially used agent 1
- Retreat with a 7-day course of a different antimicrobial 1
Symptomatic Treatment
- For women with mild-moderate symptoms, ibuprofen alone may be considered as an alternative to immediate antibiotics after discussing risks and benefits 1, 3
- This approach carries low complication risk but requires patient understanding of when to seek further care 3