Management of Urinary Tract Infections in Adults
First-Line Treatment for Uncomplicated Cystitis
For acute uncomplicated cystitis in adult women, nitrofurantoin 100mg twice daily for 5 days is the preferred first-line agent, with fosfomycin 3g single dose or trimethoprim-sulfamethoxazole (TMP-SMX) 160/800mg twice daily for 3 days as alternatives when local resistance patterns permit. 1, 2
Specific Antibiotic Regimens
Nitrofurantoin monohydrate/macrocrystals 100mg twice daily for 5-7 days is recommended as first-line therapy due to minimal collateral damage to normal flora and preserved susceptibility patterns 1, 2, 3
Fosfomycin 3g as a single oral dose provides convenient single-dose therapy with activity against ESBL-producing organisms, though bacterial eradication rates are lower than other first-line agents 1, 2, 3
TMP-SMX 160/800mg twice daily for 3 days is effective but should NOT be used empirically if local resistance exceeds 20% or if the patient received it in the preceding 3-6 months 1, 4, 2
Trimethoprim alone 100mg twice daily for 3 days can be used when sulfa allergy exists 2, 3
Critical Pitfalls to Avoid
Do NOT use fluoroquinolones as first-line therapy for uncomplicated cystitis; reserve them for pyelonephritis or more invasive infections due to resistance concerns and adverse effect profiles 1, 2, 3
Do NOT use oral β-lactams (amoxicillin-clavulanate, cephalexin) as first-line empiric therapy as they are less effective than the recommended first-line agents 1, 3
Do NOT use fosfomycin for complicated UTIs, pyelonephritis, or infections with non-fermenting organisms as it lacks sufficient efficacy data beyond uncomplicated cystitis 1, 5
Diagnosis and Testing Strategy
When to Diagnose Without Testing
- Women with typical symptoms (dysuria, frequency, urgency, suprapubic pain) without vaginal discharge can be diagnosed and treated without office visit or urine culture, as self-diagnosis has >90% accuracy 2, 3
When Urine Culture is Required
Obtain urine culture and susceptibility testing before treatment in these situations: 6, 2
- Recurrent UTI (≥2 episodes in 6 months or ≥3 in 1 year)
- Treatment failure
- History of resistant isolates
- Atypical presentation
- All men with UTI symptoms
- All adults ≥65 years with UTI
Obtain repeat urine studies when initial specimen suggests contamination, with consideration for catheterized specimen 6
Treatment for Pyelonephritis (Upper UTI)
For outpatient management of pyelonephritis, fluoroquinolones are recommended if local resistance is <10%, with ciprofloxacin 500mg twice daily for 5-7 days or levofloxacin 750mg once daily for 5 days. 1, 7
TMP-SMX 160/800mg twice daily for 7-14 days can be used ONLY if the pathogen is known to be susceptible 1, 4
Oral β-lactams should NOT be used as first-line for pyelonephritis as they are less effective than fluoroquinolones or TMP-SMX 1
Special Population: Men with UTI
All men with lower UTI symptoms should receive antibiotics with urine culture guiding antibiotic choice, as urethritis and prostatitis must be considered. 2
- First-line antibiotics for uncomplicated UTI in men: trimethoprim, TMP-SMX, or nitrofurantoin for 7 days (longer than the 3-5 days used in women) 2
Special Population: Adults ≥65 Years
Nonfrail adults ≥65 years with uncomplicated UTI require urine culture with susceptibility testing to adjust antibiotics after initial empiric treatment, but first-line agents and durations do not differ from younger adults. 2
- Asymptomatic bacteriuria is highly prevalent in older adults and should NOT be treated, as treatment shows no benefit over placebo 6
Recurrent UTI Management
Documentation Requirements
Document positive urine cultures associated with prior symptomatic episodes to make a diagnosis of recurrent UTI 6
Obtain urinalysis, urine culture and sensitivity with each symptomatic acute cystitis episode prior to initiating treatment in patients with recurrent UTI 6
Prophylaxis Options
Patient-initiated treatment (self-start) may be offered to select recurrent UTI patients with acute episodes while awaiting urine cultures 6
Continuous antibiotic prophylaxis is effective in reducing recurrent UTI episodes, emergency room visits, and hospital admissions, though it carries risks of adverse effects and antimicrobial resistance 8
Non-antibiotic prevention strategies include: increased fluid intake, cranberry products, and methenamine hippurate 2
When NOT to Perform Invasive Testing
- Cystoscopy and upper tract imaging should NOT be routinely obtained in otherwise healthy women presenting with recurrent UTI 6
Antimicrobial Stewardship Principles
Antibiotic deescalation and transition to oral therapy should be implemented when clinically appropriate, as multiple RCTs demonstrate comparable outcomes with reduced hospital length of stay and adverse events. 6
Key Stewardship Strategies
Avoid treating asymptomatic bacteriuria except in pregnant patients and those undergoing invasive urologic procedures with expected mucosal bleeding 6
Use shortest effective duration: 3-5 days for uncomplicated cystitis depending on agent, 5-7 days for pyelonephritis with fluoroquinolones 1, 2
Consider symptomatic treatment with NSAIDs and delayed antibiotics for uncomplicated cystitis, as risk of complications is low 2
Treatment of Multidrug Resistant Organisms
For ESBL-producing Enterobacteriaceae causing uncomplicated cystitis, nitrofurantoin, fosfomycin, or pivmecillinam (where available) remain effective oral options. 1, 5
Duration of treatment for UTIs caused by MDR organisms does NOT need to be modified compared to non-resistant organisms, provided the antimicrobial has demonstrated activity and proven efficacy for UTIs 6
For carbapenem-resistant Enterobacteriaceae (CRE): treatment options include ceftazidime-avibactam, meropenem-vaborbactam, imipenem-cilastatin-relebactam, cefiderocol, aminoglycosides including plazomicin, and fosfomycin 5, 9