What is the recommended oral antibiotic regimen for acute pyelonephritis (infection of the kidney)?

From the Guidelines

For uncomplicated pyelonephritis, the recommended oral antibiotic regimen is ciprofloxacin 500–750 mg twice daily for 7 days, as suggested by the European Association of Urology guidelines 1. This regimen is preferred due to its excellent urinary tract penetration and broad coverage against gram-negative organisms, which are the most common causative organisms of pyelonephritis. The choice of antibiotic should be based on local resistance patterns, and fluoroquinolone resistance should be less than 10% for empirical use 1. If fluoroquinolone resistance is high, an initial intravenous dose of a long-acting parenteral antimicrobial, such as ceftriaxone, should be administered before starting oral therapy 1. Alternative options include levofloxacin 750 mg once daily for 5 days, trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days, cefpodoxime 200 mg twice daily for 10 days, or ceftibuten 400 mg once daily for 10 days, as outlined in the European Association of Urology guidelines 1. It is essential to obtain a urine culture to guide therapy and ensure adequate hydration during treatment, and to follow up to confirm symptom resolution 1. These antibiotics target the most common causative organism, Escherichia coli, which accounts for about 80% of cases, and are suitable for patients who are hemodynamically stable, can tolerate oral medications, and do not have complicating factors like pregnancy, immunosuppression, or anatomical abnormalities.

From the FDA Drug Label

14.7 Complicated Urinary Tract Infections and Acute Pyelonephritis: 5 Day Treatment Regimen To evaluate the safety and efficacy of the higher dose and shorter course of levofloxacin, 1109 patients with cUTI and AP were enrolled in a randomized, double-blind, multicenter clinical trial conducted in the U.S. from November 2004 to April 2006 comparing levofloxacin 750 mg I.V. or orally once daily for 5 days (546 patients) with ciprofloxacin 400 mg I.V. or 500 mg orally twice daily for 10 days (563 patients).

Oral antibiotic regimen for pyelonephritis:

• Levofloxacin can be used as an oral antibiotic regimen for pyelonephritis, with a recommended dose of 750 mg orally once daily for 5 days 2.
• The bacteriologic cure rates for levofloxacin in the treatment of acute pyelonephritis are presented in Table 20 and Table 21 2.
• A 10-day treatment regimen of levofloxacin 250 mg orally once daily has also been evaluated in clinical trials 2.

From the Research

Oral Antibiotic Regimens for Pyelonephritis

• The most common etiologic cause of pyelonephritis is infection with Escherichia coli 3.
• Outpatient oral antibiotic therapy with a fluoroquinolone is successful in most patients with mild uncomplicated pyelonephritis 3.
• Other effective alternatives for oral antibiotic therapy include:
  • Extended-spectrum penicillins
  • Amoxicillin-clavulanate potassium
  • Cephalosporins
  • Trimethoprim-sulfamethoxazole 3
• A 7-day ciprofloxacin regimen was associated with greater bacteriologic and clinical cure rates than a 14-day trimethoprim-sulfamethoxazole regimen for acute uncomplicated pyelonephritis in women 4.
• Cephalosporins, such as cefaclor and cephalexin, have shown comparable clinical success rates for the outpatient treatment of pyelonephritis, ranging from 83% to 95% 5.
• Cephalosporins may be viable treatment options for the management of uncomplicated pyelonephritis, with no trials reporting inferiority of clinical treatment outcomes compared to fluoroquinolones or trimethoprim-sulfamethoxazole 6.
• Failure of therapy for pyelonephritis occurred more often in the fluoroquinolone and trimethoprim-sulfamethoxazole group than in the cephalosporin group 7.

Key Considerations

• Urine cultures should be obtained before antibiotic therapy is initiated to guide treatment decisions 3.
• The standard duration of therapy is 7-14 days, and urine culture should be repeated 1-2 weeks after completion of antibiotic therapy 3.
• Treatment failure may be caused by resistant organisms, underlying anatomic/functional abnormalities, or immunosuppressed states, and may require a change in antibiotics or surgical intervention 3.