Treatment of Pyelonephritis
For outpatient treatment of acute uncomplicated pyelonephritis, oral ciprofloxacin 500 mg twice daily for 7 days is the preferred first-line therapy in areas where fluoroquinolone resistance is below 10%. 1, 2
Initial Assessment
- Always obtain urine culture and susceptibility testing before initiating antibiotics to guide definitive therapy and adjust empirical treatment based on results 1, 2
- Tailor initial empirical therapy based on local resistance patterns and severity of illness at presentation 1
Outpatient Treatment Regimens
First-Line Fluoroquinolone Options (when local resistance <10%)
Ciprofloxacin 500 mg orally twice daily for 7 days is the standard regimen 1, 2, 3
Once-daily fluoroquinolone alternatives:
When Fluoroquinolone Resistance Exceeds 10%
- Administer one initial IV dose of a long-acting parenteral agent before starting oral fluoroquinolone therapy: 1, 2
- Some experts recommend continuing the parenteral agent until susceptibility data are available, though this approach lacks robust study support 1
Alternative Oral Therapy
- Trimethoprim-sulfamethoxazole 160/800 mg (double-strength) orally twice daily for 14 days is appropriate only if the uropathogen is known to be susceptible 1, 2
Inpatient Treatment Regimens
Initial IV Therapy Options
- Fluoroquinolones: Levofloxacin 750 mg IV once daily or ciprofloxacin 400 mg IV every 12 hours 2, 6
- Aminoglycosides: Gentamicin 5-7 mg/kg IV once daily, with or without ampicillin 2, 6
- Extended-spectrum cephalosporins: Ceftriaxone 1-2 g IV once daily 2, 6
- Extended-spectrum penicillins with or without aminoglycoside 2, 6
- Carbapenems for suspected multidrug-resistant organisms 2
Transition to Oral Therapy
- Switch to oral antibiotics when the patient is clinically improving and able to tolerate oral intake 6
- Base oral regimen selection on culture susceptibility results 1, 2
Treatment Duration
- Fluoroquinolones: 5-7 days depending on the specific agent and formulation 1, 2
- Trimethoprim-sulfamethoxazole: 14 days (traditional duration) 1, 2
- β-lactams: 10-14 days (longer duration needed due to inferior efficacy compared to fluoroquinolones) 2, 6
Indications for Hospitalization
- Severe illness or sepsis 6, 7
- Persistent vomiting or inability to tolerate oral therapy 6, 7
- Complicated infections (obstruction, abscess, underlying anatomic abnormalities) 6, 7
- Failed outpatient treatment 6
- Pregnancy (significantly elevated risk of severe complications) 7
- Extremes of age 6
- Suspected multidrug-resistant organism 7
Common Pitfalls to Avoid
- Failing to obtain urine cultures before starting antibiotics prevents appropriate tailoring of therapy 2
- Not considering local resistance patterns when selecting empirical therapy leads to treatment failures 2
- Using fluoroquinolones empirically in areas with >10% resistance without an initial parenteral dose increases risk of inadequate coverage 2
- Using oral β-lactams as monotherapy without initial parenteral dosing results in inferior outcomes 2
- Not adjusting therapy based on culture results perpetuates inappropriate antibiotic use 2
- Inadequate treatment duration, especially with β-lactam agents, increases relapse rates 2
- Using trimethoprim-sulfamethoxazole or β-lactams empirically given high resistance rates (48-55% for E. coli to ciprofloxacin and cotrimoxazole in some regions) 5
Follow-Up
- Repeat urine culture 1-2 weeks after completion of antibiotic therapy 6
- Most patients respond within 48-72 hours; lack of response warrants repeat cultures, imaging studies, and consideration of alternative diagnoses 6, 7
- Treatment failure may indicate resistant organisms, underlying anatomic/functional abnormalities, or immunosuppression 6