Management of Urinary Tract Infection
Initial Diagnostic Approach
Obtain a urine culture before initiating antibiotics to guide therapy adjustments based on susceptibility results. 1, 2
- Urinalysis should assess white blood cells, red blood cells, and nitrite for routine diagnosis 1
- In febrile infants and children (2-24 months), a threshold of ≥50,000 CFUs/mL of a single urinary pathogen indicates significant bacteriuria 1
- Coagulase-negative staphylococci, Lactobacillus species, and Corynebacterium species are not considered clinically relevant isolates in otherwise healthy patients 1, 3
- In men, perform digital rectal examination to evaluate for prostate involvement, as this affects treatment duration 2
Treatment by Patient Population
Uncomplicated Cystitis in Women
First-line agents include fosfomycin 3g single dose, nitrofurantoin 100mg twice daily for 5 days, or pivmecillinam 400mg three times daily for 3-5 days. 1
- Fosfomycin trometamol 3g single dose is recommended only for women with uncomplicated cystitis 1
- Nitrofurantoin options: 50-100mg four times daily for 5 days, or 100mg twice daily for 5 days (monohydrate/macrocrystals or prolonged release formulations) 1
- Pivmecillinam 400mg three times daily for 3-5 days 1
Alternative agents (use only if local E. coli resistance <20%): 1
- Cephalosporins (e.g., cefadroxil 500mg twice daily for 3 days) 1
- Trimethoprim 200mg twice daily for 5 days (avoid in first trimester of pregnancy) 1
- Trimethoprim-sulfamethoxazole 160/800mg twice daily for 3 days (avoid in last trimester of pregnancy) 1
UTI in Men
Trimethoprim-sulfamethoxazole 160/800mg twice daily for 7-14 days is the first-line treatment for men with UTI. 1, 2
- Standard duration is 14 days when prostatitis cannot be excluded, which applies to most male UTI presentations 1, 2
- A shorter duration of 7 days may be considered only if the patient becomes afebrile within 48 hours with clear clinical improvement 2
- However, recent evidence shows 7-day ciprofloxacin was inferior to 14-day therapy for short-term clinical cure in men (86% vs 98%, p=0.025) 2
Alternative oral options: 2
- Cefpodoxime 200mg twice daily for 10 days 2
- Ceftibuten 400mg once daily for 10 days 2
- Fluoroquinolones (ciprofloxacin or levofloxacin) only when local resistance <10% and patient has not used them in past 6 months 2
Critical considerations for men: 1, 2
- UTIs in men are considered complicated infections due to anatomical factors, requiring longer treatment 2
- The microbial spectrum is broader with increased likelihood of antimicrobial resistance 2
- Common uropathogens include E. coli, Proteus species, Klebsiella species, Pseudomonas species, and Enterococcus species 2
Uncomplicated Pyelonephritis
Fluoroquinolones should be considered as first-line therapy for uncomplicated pyelonephritis in nonpregnant, premenopausal women without urological abnormalities. 1, 4
- Presents with fever >38°C, chills, flank pain, nausea, vomiting, or costovertebral angle tenderness, with or without cystitis symptoms 1
- Urinalysis including white/red blood cells and nitrite is recommended for diagnosis 1
Febrile Infants and Children (2-24 months)
Oral and parenteral routes are equally efficacious; base the choice on practical considerations including patient's ability to retain oral intake. 1
Parenteral options (for toxic-appearing or unable to retain oral intake): 1
- Ceftriaxone 75mg/kg every 24 hours 1
- Cefotaxime 150mg/kg per day divided every 6-8 hours 1
- Gentamicin 7.5mg/kg per day divided every 8 hours 1
Oral options: 1
- Amoxicillin-clavulanate 20-40mg/kg per day in 3 doses 1
- Trimethoprim-sulfamethoxazole 6-12mg/kg trimethoprim and 30-60mg/kg sulfamethoxazole per day in 2 doses 1
- Cefixime 8mg/kg per day in 1 dose 1
- Cefpodoxime 10mg/kg per day in 2 doses 1
Treatment duration: 7-14 days 1
Recurrent UTI Prevention
Use non-antimicrobial interventions first before resorting to antimicrobial prophylaxis. 1
Strong recommendations: 1
- Diagnose recurrent UTI via urine culture 1
- Use vaginal estrogen replacement in postmenopausal women 1
- Use immunoactive prophylaxis (e.g., OM-89) to reduce recurrent UTI in all age groups 1, 4
- Use methenamine hippurate in women without urinary tract abnormalities 1
- Use continuous or postcoital antimicrobial prophylaxis only when non-antimicrobial interventions have failed 1
Weak recommendations: 1
- Advise premenopausal women to increase fluid intake 1
- Consider probiotics containing strains of proven efficacy for vaginal flora regeneration 1
- Cranberry products may reduce episodes, but evidence quality is low with contradictory findings 1
- D-mannose may reduce episodes, but evidence is weak and contradictory 1
Critical Pitfalls to Avoid
Do not treat asymptomatic bacteriuria (except in pregnant women and patients undergoing invasive urinary procedures), as it increases symptomatic infection risk and bacterial resistance. 2, 3
Avoid fluoroquinolones as first-line agents due to FDA warnings about disabling and serious adverse effects, creating an unfavorable risk-benefit ratio for uncomplicated UTIs. 2
Do not use beta-lactams (including cephalexin) as first-line agents due to inferior efficacy compared to nitrofurantoin, fosfomycin, or trimethoprim-sulfamethoxazole. 2
Avoid inadequate treatment duration in men, as this leads to persistent or recurrent infection, particularly when prostate involvement is present. 2
Do not perform extensive routine workup (cystoscopy, full abdominal ultrasound) in women younger than 40 years with recurrent UTI and no risk factors. 1
Failing to obtain pre-treatment cultures complicates management if empiric therapy fails. 2, 3
Special Considerations
Pregnancy
- Recommended treatment includes cephalosporins (e.g., cefuroxime) or nitrofurantoin 4
- Avoid trimethoprim in first trimester and trimethoprim-sulfamethoxazole in last trimester 1
Catheter-Associated UTI
- For catheters in place ≥2 weeks, replace the catheter and obtain culture from fresh catheter before initiating therapy 3