What is the diagnosis and treatment for Pyelonephritis (infection of the kidney)?

From the Guidelines

Pyelonephritis should be diagnosed and treated promptly with antibiotics, with the choice of antibiotic regimen depending on the severity of the infection and local resistance patterns, as recommended by the European Association of Urology guidelines in 2024 1.

Diagnosis

The diagnosis of pyelonephritis typically involves urinalysis, including assessment of white and red blood cells and nitrite, as well as a urine culture and antimicrobial susceptibility testing 1. Imaging studies such as ultrasound or computed tomography (CT) scans may also be used to evaluate the upper urinary tract and rule out complications like urinary tract obstruction or renal stone disease.

Treatment

For uncomplicated cases of pyelonephritis, oral fluoroquinolones like ciprofloxacin 500mg twice daily for 7 days or trimethoprim-sulfamethoxazole (TMP-SMX) 160/800mg twice daily for 14 days are commonly prescribed, as long as the prevalence of fluoroquinolone resistance is less than 10% 1.

• Key considerations for treatment include:
  • The use of fluoroquinolones and cephalosporins as the only recommended antimicrobial agents for oral empiric treatment of uncomplicated pyelonephritis 1
  • The avoidance of agents like nitrofurantoin, oral fosfomycin, and pivmecillinam due to insufficient data on their efficacy 1
  • The importance of tailoring treatment to local policies and resistance patterns, especially when considering short-course antibiotic therapy 1

Hospitalization and Intravenous Antibiotics

Severe cases of pyelonephritis requiring hospitalization should be treated initially with an intravenous antimicrobial regimen, such as a fluoroquinolone, an aminoglycoside (with or without ampicillin), or an extended-spectrum cephalosporin or penicillin 1. The choice of intravenous antibiotic should be based on local resistance patterns and optimized to ensure effective treatment.

Patient Care and Follow-Up

Patients with pyelonephritis should be advised to stay hydrated to help flush bacteria from the urinary system and complete the full antibiotic course even if symptoms improve quickly to prevent recurrence and antibiotic resistance 1. Those with persistent symptoms after 48-72 hours of treatment should be reevaluated for complications like abscess formation or antibiotic resistance.

From the FDA Drug Label

1. 11 Acute Pyelonephritis: 5 or 10 Day Treatment Regimen Levofloxacin tablets are indicated for the treatment of acute pyelonephritis caused by Escherichia coli, including cases with concurrent bacteremia [see Clinical Studies (14.7,14.8)].

2. 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).

The diagnosis of Pyelonephritis (infection of the kidney) is typically based on clinical presentation, laboratory tests, and imaging studies. The treatment for Pyelonephritis is usually with antibiotics, and levofloxacin is one of the options.

• The recommended treatment regimen for acute pyelonephritis with levofloxacin is 5 or 10 days.
• The dosage is 750 mg orally once daily for 5 days or 250 mg orally once daily for 10 days.
• Levofloxacin is effective against Escherichia coli, including cases with concurrent bacteremia 2.

From the Research

Diagnosis of Pyelonephritis

• The diagnosis of pyelonephritis is typically made based on a combination of clinical presentation, laboratory tests, and imaging studies 3, 4, 5.
• The most common symptoms of pyelonephritis include fever, flank pain, and urinary tract infection symptoms such as dysuria and frequency 3, 4.
• Laboratory tests such as urinalysis and urine culture are essential for diagnosing pyelonephritis and guiding antibiotic therapy 3, 4, 5.
• Imaging studies such as computed tomography (CT) scans may be necessary in some cases to rule out complications or alternative diagnoses 4, 5.

Treatment of Pyelonephritis

• The treatment of pyelonephritis typically involves antibiotic therapy, with the choice of antibiotic depending on the severity of the infection, the presence of underlying medical conditions, and the results of antimicrobial susceptibility testing 3, 6, 4, 7, 5.
• Outpatient treatment with oral antibiotics such as fluoroquinolones or trimethoprim/sulfamethoxazole may be appropriate for patients with mild, uncomplicated pyelonephritis 3, 4, 5.
• Inpatient treatment with parenteral antibiotics such as ceftriaxone or aminoglycosides may be necessary for patients with severe infections, sepsis, or underlying medical conditions that increase the risk of complications 3, 6, 7, 5.
• The duration of antibiotic therapy typically ranges from 7 to 14 days, depending on the severity of the infection and the patient's response to treatment 3, 6.

Antibiotic Resistance and Treatment Failure

• Antibiotic resistance is a significant concern in the treatment of pyelonephritis, with high rates of resistance to commonly used antibiotics such as fluoroquinolones and trimethoprim/sulfamethoxazole 7, 5.
• Treatment failure may occur due to antibiotic resistance, underlying anatomic or functional abnormalities, or immunosuppressed states 3, 7.
• In cases of treatment failure, repeat blood and urine cultures, as well as imaging studies, may be necessary to guide further treatment and evaluate for potential complications 3, 5.