Management of Pyelonephritis
The recommended approach to managing pyelonephritis includes obtaining urinalysis and urine culture, initiating empiric antibiotic therapy based on local resistance patterns, and adjusting treatment duration according to disease severity (7-14 days for uncomplicated cases and 10-21 days for complicated cases). 1
Diagnosis
Key clinical features:
Diagnostic testing:
- Urinalysis: Leukocyte esterase and nitrite tests combined have 75-84% sensitivity and 82-98% specificity 3
- Urine culture: Essential before starting antibiotics to guide therapy 1, 2
- Blood cultures: Reserve for immunocompromised patients, uncertain diagnosis, or suspected hematogenous infection 3
- Imaging: Not necessary unless symptoms fail to improve with appropriate therapy or recur after initial improvement 2
Treatment Algorithm
1. Determine Treatment Setting
Outpatient management for patients with:
- Uncomplicated infection
- Ability to tolerate oral medications
- No sepsis
- No complicating factors
Inpatient management for patients with:
2. Empiric Antibiotic Selection
Outpatient (Oral) Therapy:
First-line options (when local resistance <20%):
- Nitrofurantoin 100 mg twice daily for 5 days
- Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days
- Fosfomycin 3 g single dose 1
If local fluoroquinolone resistance ≤10%:
If local resistance >10%:
- Initial dose of ceftriaxone or gentamicin (IV), followed by oral fluoroquinolone 2
Alternative options (based on susceptibility):
- Cephalexin 500 mg four times daily
- Amoxicillin-clavulanate 1
Inpatient (IV) Therapy:
First-line options:
- Fluoroquinolone (e.g., ciprofloxacin)
- Aminoglycoside with or without ampicillin
- Third-generation cephalosporin 3
For suspected ESBL-producing organisms:
- Carbapenems or other appropriate broad-spectrum antibiotics 4
For pediatric patients:
- IV: 6-10 mg/kg (maximum 400 mg) every 8 hours
- Oral: 10-20 mg/kg (maximum 750 mg) every 12 hours 5
3. Treatment Duration
Uncomplicated pyelonephritis: 7 days 1, 6
- A randomized controlled trial demonstrated that 7-day ciprofloxacin treatment was non-inferior to 14-day treatment for acute pyelonephritis in women 6
Pediatric pyelonephritis: 10-21 days 5
4. Dosage Adjustment for Renal Impairment
For patients with impaired renal function, adjust dosing as follows:
| Creatinine Clearance | Ciprofloxacin Dosing |
|---|---|
| >50 mL/min | Standard dosing |
| 30-50 mL/min | 250-500 mg q12h |
| 5-29 mL/min | 250-500 mg q18h |
| Hemodialysis/PD | 250-500 mg q24h (after dialysis) [5] |
5. Follow-up and Treatment Failure
- Repeat urine culture 1-2 weeks after completion of therapy 3
- If no improvement within 48-72 hours:
- Obtain imaging (typically contrast-enhanced CT)
- Repeat cultures
- Consider alternative diagnoses
- Evaluate for urinary obstruction requiring urgent decompression 4
Special Considerations
- Pregnancy: Admit for initial parenteral therapy due to significantly elevated risk of complications 4
- Recurrent infections: Consider imaging and cystoscopy to evaluate for anatomic abnormalities 1
- Asymptomatic bacteriuria: Should not be treated except in pregnant women and patients undergoing urologic procedures 1
Common Pitfalls to Avoid
- Using fluoroquinolones as first-line therapy in areas with high resistance rates (>10%)
- Failing to obtain urine culture before initiating antibiotics
- Treating asymptomatic bacteriuria (except in pregnancy or before urologic procedures)
- Prolonged antibiotic courses that increase risk of adverse effects and resistance without improving outcomes
- Neglecting to adjust antibiotic dosing in patients with renal impairment