What is the recommended treatment for Pylonephritis?

Treatment of Pyelonephritis

Immediate Risk Stratification

The first critical step is determining whether the pyelonephritis is uncomplicated or complicated, as this fundamentally changes management and prognosis. 1

• Uncomplicated pyelonephritis is defined as infection without structural/functional urinary tract abnormalities, no immunosuppression, pregnancy, diabetes, signs of sepsis, or hemodynamic instability 1
• Complicated pyelonephritis includes any of the above risk factors and requires more aggressive management 1

Essential Diagnostic Workup

• Obtain urine culture with antimicrobial susceptibility testing in ALL patients before initiating antibiotics 1, 2
• Blood cultures should be reserved for patients with uncertain diagnosis, immunocompromised status, or suspected hematogenous infection 3
• Imaging is indicated if: patient remains febrile after 72 hours of appropriate therapy, immediate clinical deterioration occurs, obstruction or abscess is suspected, or frank hematuria is present 1

First-Line Empiric Antibiotic Therapy

For Outpatient Oral Treatment (Uncomplicated Cases)

The preferred first-line options are fluoroquinolones: 1, 2

• Ciprofloxacin 500-750 mg twice daily for 7 days 1, 4
• Levofloxacin 750 mg once daily for 5 days (offers once-daily dosing advantage for improved adherence) 1, 2

Alternative oral options (less preferred due to lower efficacy): 1

• Cefpodoxime 200 mg twice daily for 10 days 1
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days (only if susceptibility is confirmed) 2, 5

Critical Caveat on Fluoroquinolone Resistance

• If local fluoroquinolone resistance exceeds 10%, administer one initial IV dose of ceftriaxone 1-2g before starting oral fluoroquinolone therapy 2, 5
• In France (2011), approximately 10% of community E. coli were resistant to ciprofloxacin, with hospital rates reaching 18% 6

For Inpatient Intravenous Treatment

Initial empiric IV regimens include: 1

• Fluoroquinolones (IV formulation)
• Extended-spectrum cephalosporins (e.g., ceftriaxone)
• Extended-spectrum penicillins
• Aminoglycosides 1

Treatment Duration

• Fluoroquinolones: 5-7 days 1, 2
• Trimethoprim-sulfamethoxazole: 14 days 1, 2
• Oral cephalosporins: 10 days 1
• β-lactam antibiotics: 10-14 days 2

Important note: Short-course therapy (5-7 days) achieves equivalent clinical and microbiological success but has higher recurrence rates at 4-6 weeks 1

Indications for Hospitalization

Admit patients with: 3, 7

• Complicated infections
• Signs of sepsis or hemodynamic instability
• Persistent vomiting (unable to tolerate oral therapy)
• Failed outpatient treatment
• Extremes of age
• Urinary tract obstruction requiring urgent decompression 7

Special Populations Requiring Modified Management

Pregnant Patients

• Require hospital admission 1
• Use ultrasound or MRI for imaging (avoid CT) 1
• Initial parenteral therapy is mandatory 1
• Significantly elevated risk of severe complications 7

Patients with Diabetes or Chronic Kidney Disease

• Higher risk for complications 1
• Require IV therapy and close monitoring 1
• May need dose adjustments for renal impairment 1

Breastfeeding Patients

• Fluoroquinolones should be used with caution but are acceptable when benefits outweigh risks 5
• Same dosing regimens as non-breastfeeding patients apply 5

Pediatric Patients

• Complicated UTI/pyelonephritis: 10-20 mg/kg orally every 12 hours (maximum 750 mg per dose) for 10-21 days 4
• Ciprofloxacin is not first-choice in pediatrics due to increased joint-related adverse events 4

Critical Antibiotics to AVOID

• Amoxicillin or ampicillin should NOT be used for empirical treatment due to high resistance rates 2
• Nitrofurantoin, oral fosfomycin, and pivmecillinam should be avoided due to insufficient efficacy data 5
• β-lactam antibiotics are less effective than fluoroquinolones and should be used with caution 2

Monitoring and Follow-Up

• Most patients respond within 48-72 hours 7
• Repeat urine culture 1-2 weeks after completion of antibiotic therapy 3
• If no response after 72 hours: obtain repeat blood and urine cultures, consider imaging studies, and evaluate for resistant organisms, anatomic abnormalities, or immunosuppression 1, 3

Management of Mixed Urogenital Flora

• Mixed flora often represents contamination, but true polymicrobial infections occur in patients with urinary tract abnormalities, recent instrumentation, indwelling catheters, or immunocompromised status 2
• For true polymicrobial infections, broader-spectrum coverage may be necessary until culture results are available 2

Conversion from IV to Oral Therapy

Patients started on IV therapy may be switched to oral ciprofloxacin when clinically indicated: 4

• 200 mg IV every 12 hours = 250 mg oral every 12 hours
• 400 mg IV every 12 hours = 500 mg oral every 12 hours
• 400 mg IV every 8 hours = 750 mg oral every 12 hours 4