What is the recommended management for an adult patient with an uncomplicated urinary tract infection (UTI)?

Management of Urinary Tract Infections

For uncomplicated cystitis in adult women, nitrofurantoin 100 mg twice daily for 5 days is the preferred first-line agent, as it demonstrates robust efficacy while sparing broader-spectrum antibiotics for more serious infections. 1, 2

Classification and Diagnostic Approach

Distinguish between uncomplicated and complicated UTI before initiating treatment:

• Uncomplicated UTI occurs in women with normal genitourinary anatomy, no pregnancy, and no immunosuppression presenting with dysuria, frequency, urgency, or suprapubic pain 2
• Complicated UTI involves structural/functional urinary abnormalities, immunosuppression, pregnancy, male sex, catheter-associated infection, diabetes mellitus, recent instrumentation, or multidrug-resistant organisms 1, 2

Obtain urine culture only when:

• Symptoms suggest pyelonephritis (fever, flank pain, costovertebral angle tenderness) 2
• Patient has complicated UTI risk factors 1
• Treatment failure occurs after 72 hours 1

Do not obtain urine culture for:

• Uncomplicated cystitis in women (clinical diagnosis suffices) 2, 3
• Asymptomatic bacteriuria except in pregnant women, preschool children, or patients undergoing urologic/gynecologic surgery 2

Empirical Treatment for Uncomplicated Cystitis

First-line antibiotic options (choose based on local resistance patterns):

• Nitrofurantoin monohydrate/macrocrystals: 100 mg twice daily for 5 days 1, 2, 3
• TMP/SMX: 160/800 mg twice daily for 3 days (only if local resistance <20%) 1, 4, 3
• Fosfomycin trometamol: 3 g single dose 1, 3
• Pivmecillinam: 200 mg twice daily for 3 days 1

Second-line options (reserve for specific situations):

• Fluoroquinolones: Ciprofloxacin 250-500 mg twice daily for 3 days 1, 5, 3
  • Reserve for more invasive infections due to ecological collateral damage 1
  • Should not be first-line for simple cystitis 2, 3

Avoid β-lactams (amoxicillin-clavulanate, cefpodoxime) as empirical first-line therapy for uncomplicated cystitis—they demonstrate inferior efficacy compared to other agents. 1, 3

Empirical Treatment for Pyelonephritis

For outpatient oral therapy (mild-moderate severity):

• Ciprofloxacin: 500-750 mg twice daily for 7 days 1, 5
• Levofloxacin: 750 mg once daily for 5 days 1
• TMP/SMX: 160/800 mg twice daily for 14 days (if local resistance <10%) 1, 4
• Cefpodoxime: 200 mg twice daily for 10 days 1

Consider initial IV dose of ceftriaxone 1-2 g before transitioning to oral therapy to ensure adequate initial coverage. 1

For inpatient IV therapy (severe illness, unable to tolerate oral):

• Ceftriaxone: 1-2 g once daily (preferred empirical choice due to low resistance rates) 1
• Ciprofloxacin: 400 mg twice daily 1
• Levofloxacin: 750 mg once daily 1
• Piperacillin/tazobactam: 3.375-4.5 g three times daily 1

Duration: β-lactams for 7 days; fluoroquinolones for 5-7 days 1

Reserve antipseudomonal agents (cefepime, carbapenems, ceftolozane/tazobactam) only for patients with risk factors for nosocomial pathogens or early culture results indicating multidrug-resistant organisms. 1

Management of Complicated UTI

Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded) 1

Mandatory steps:

• Obtain urine culture and susceptibility testing before initiating therapy 1
• Address underlying urological abnormality or complicating factor 1
• Tailor empirical therapy based on local resistance patterns and patient-specific risk factors 1

Empirical antibiotic selection follows same principles as pyelonephritis, but consider broader spectrum if:

• Healthcare-associated infection 1
• Recent antibiotic exposure 1
• Known colonization with resistant organisms 1

Shorten duration to 7 days if patient is hemodynamically stable and afebrile for ≥48 hours, particularly when relative contraindications to prolonged antibiotic use exist. 1

Catheter-Associated UTI

Diagnostic limitations:

• Urinalysis has very low specificity but excellent negative predictive value 1
• Negative UA rules out CAUTI in patients with functioning bone marrow 1
• Positive UA does not confirm CAUTI—bacteriuria is almost always present regardless of symptoms 1

Only treat when systemic symptoms present: fever, rigors, altered mental status, flank pain, costovertebral angle tenderness, acute hematuria, pelvic discomfort 1

Treatment duration: Insufficient evidence for clear recommendation; apply complicated UTI principles (7-14 days) 1

Special Populations

Men with UTI:

• Treat for 7-14 days (14 days preferred when prostatitis cannot be excluded) 1
• Consider complicated UTI by definition 1, 2

Women with diabetes:

• Treat similarly to women without diabetes if no voiding abnormalities present 3
• Consider as complicated UTI if structural abnormalities or immunosuppression exists 1, 2

Pregnant women:

• Treat asymptomatic bacteriuria 2
• Avoid fluoroquinolones and nitrofurantoin near term 2

Gram-negative bacteremia from urinary source:

• 7 days of appropriate antimicrobial therapy 1

Critical Pitfalls to Avoid

Do not:

• Treat asymptomatic bacteriuria in non-pregnant, non-surgical patients 2
• Use fluoroquinolones as first-line for simple cystitis 1, 2, 3
• Obtain imaging routinely—only if symptoms persist beyond 72 hours or concern for abscess/obstruction 1
• Use broad-spectrum antibiotics for extended durations when unnecessary 2
• Test urine in febrile patients without urinary symptoms, especially elderly patients 2

Always:

• Consider local resistance patterns when selecting empirical therapy 1, 2
• Adjust antibiotic doses for renal function 2
• Reassess at 48-72 hours if symptoms not improving 1