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

From the Guidelines

Pyelonephritis should be treated with oral fluoroquinolones, such as ciprofloxacin (500mg twice daily for 7 days) or levofloxacin (750mg once daily for 5 days), for uncomplicated cases managed as outpatients, as recommended by the European Association of Urology guidelines 1. For severe cases requiring hospitalization, intravenous antibiotics such as ceftriaxone (1-2g daily) should be used until clinical improvement, followed by oral therapy to complete 7-14 days total 1. The choice of antibiotic should be based on local resistance data and tailored to the specific infecting uropathogen, with fluoroquinolones being the preferred class for oral therapy in regions with low resistance rates 1. Patients should increase fluid intake, take analgesics for pain relief, and complete the full antibiotic course even after symptoms improve. Recurrent infections warrant urologic evaluation to identify anatomical abnormalities or obstructions. The most common causative organism is Escherichia coli, which explains why empiric therapy targets gram-negative bacteria until culture results guide specific treatment. In areas with high fluoroquinolone resistance, an initial dose of a long-acting parenteral antimicrobial, such as ceftriaxone, should be administered before starting oral therapy 1. Oral beta-lactam agents are less effective than other available agents for treatment of pyelonephritis and should be used with caution, with an initial intravenous dose of a long-acting parenteral antimicrobial recommended if used 1. Key considerations in managing pyelonephritis include:

• Prompt initiation of antibiotic therapy
• Selection of antibiotics based on local resistance patterns and susceptibility testing
• Adequate duration of therapy to prevent recurrence and complications
• Supportive care, including hydration and pain management
• Urologic evaluation for recurrent infections or complications.

From the FDA Drug Label

CLINICAL STUDIES Complicated Urinary Tract Infection and Pyelonephritis – Efficacy in Pediatric Patients: Ciprofloxacin, administered I. V. and/or orally, was compared to a cephalosporin for treatment of complicated urinary tract infections (cUTI) and pyelonephritis in pediatric patients 1 to 17 years of age (mean age of 6 ± 4 years). The clinical success and bacteriologic eradication rates in the Per Protocol population were similar between ciprofloxacin and the comparator group as shown below Clinical Success and Bacteriologic Eradication at Test of Cure (5 to 9 Days Post-Therapy) CiprofloxacinComparator

• Patients with baseline pathogen(s) eradicated and no new infections or superinfections/total number of patients. Clinical Response at 5 to 9 Days Post-Treatment 95.7% (202/211) Bacteriologic Eradication by Patient at 5 to 9 Days Post-Treatment* 84.4% (178/211)

Ciprofloxacin is effective in treating pyelonephritis, with a clinical success rate of 95.7% and a bacteriologic eradication rate of 84.4% in pediatric patients.

• The treatment duration was 10 to 21 days (mean duration of treatment was 11 days).
• The dosage for pediatric patients with complicated urinary tract infection or pyelonephritis is 6 to 10 mg/kg I.V. every 8 hours or 10 mg/kg to 20 mg/kg orally every 12 hours. 2

From the Research

Treatment Options for Pyelonephritis

• The treatment of pyelonephritis can involve various antibiotics, including trimethoprim-sulfamethoxazole (TMP-SMX), ciprofloxacin, and oral cephalosporins 3, 4, 5.
• A study found that a 7-day course of TMP-SMX may be as effective as a 7-day course of ciprofloxacin for the treatment of pyelonephritis 3.
• Another study compared the efficacy of a 7-day ciprofloxacin regimen and a 14-day trimethoprim-sulfamethoxazole regimen for the treatment of acute uncomplicated pyelonephritis in women, and found that the ciprofloxacin regimen was associated with greater bacteriologic and clinical cure rates 4.

Comparison of Antibiotic Regimens

• A retrospective cohort study compared the outcomes of outpatients treated for pyelonephritis with oral cephalosporins versus first-line agents, and found no significant difference in urinary tract infection (UTI) recurrence rates between the two groups 5.
• A study published in the American Journal of Emergency Medicine found that treatment with cephalosporins had a lower failure rate compared to fluoroquinolones and trimethoprim-sulfamethoxazole for pyelonephritis in discharged patients from a community hospital setting 6.

Diagnosis and Prevention

• Urine culture is recommended for the diagnosis and management of pyelonephritis, recurrent urinary tract infection, and complicated urinary tract infections 7.
• Antibiotics targeted toward Escherichia coli, Proteus, Klebsiella, and Staphylococcus saprophyticus are the recommended treatment for pyelonephritis 7.
• The duration of treatment varies by specific drug and type of infection, ranging from 3 to 5 days for uncomplicated cystitis to 7 to 14 days for pyelonephritis 7.