What is the initial management for a patient with acute pyelonephritis (infection of the kidney)?

From the Guidelines

The initial management for a patient with pyelonephritis should include empiric antibiotic therapy, adequate hydration, and pain control, with oral fluoroquinolones such as ciprofloxacin 500 mg twice daily for 7 days or levofloxacin 750 mg once daily for 5 days being appropriate first-line options, as recommended by the European Association of Urology guidelines in 2024 1. For uncomplicated pyelonephritis, the choice of antibiotic should be based on local resistance patterns and the severity of illness.

• Oral fluoroquinolones are recommended for uncomplicated pyelonephritis, with ciprofloxacin 500 mg twice daily for 7 days or levofloxacin 750 mg once daily for 5 days being suitable options 1.
• Trimethoprim-sulfamethoxazole (TMP-SMX) 160/800 mg twice daily for 14 days can be used if the pathogen is known to be susceptible, but its use is limited due to high rates of resistance 1.
• For patients requiring hospitalization due to severe illness, inability to tolerate oral medications, or concern for complicated infection, intravenous options include ceftriaxone 1-2 g daily, an aminoglycoside with or without ampicillin, or a fluoroquinolone 1. Adequate hydration should be ensured either orally or intravenously, and pain management with acetaminophen or NSAIDs is recommended.
• Urine culture should be obtained before starting antibiotics to guide targeted therapy once results are available 1.
• Patients should be advised to complete the full course of antibiotics even if symptoms improve quickly, to prevent progression to sepsis or renal abscess formation 1. The rationale for aggressive antibiotic treatment is to prevent permanent kidney damage, as pyelonephritis involves bacterial infection of the renal parenchyma and collecting system 1.

From the FDA Drug Label

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)]. The initial management for a patient with pyelonephritis should be treatment with levofloxacin, as it is indicated for the treatment of acute pyelonephritis caused by Escherichia coli.

• The treatment regimen may vary depending on the severity of the infection and the presence of concurrent bacteremia.
• It is essential to note that levofloxacin is specifically indicated for the treatment of acute pyelonephritis caused by Escherichia coli, including cases with concurrent bacteremia 2.

From the Research

Initial Management for Pyelonephritis

The initial management for a patient with pyelonephritis involves several key steps:

• Urine culture with antimicrobial susceptibility testing should be performed in all patients and used to direct therapy 3
• Imaging, blood cultures, and measurement of serum inflammatory markers should not be performed in uncomplicated cases 3
• Outpatient management is appropriate in patients who have uncomplicated disease and can tolerate oral therapy 3
• Extended emergency department or observation unit stays are an appropriate option for patients who initially warrant intravenous therapy 3

Antibiotic Therapy

The choice of antibiotic therapy is crucial in the management of pyelonephritis:

• Fluoroquinolones and trimethoprim/sulfamethoxazole are effective oral antibiotics in most cases, but increasing resistance makes empiric use problematic 3
• Cephalosporins may be considered as an alternative to first-line agents, with studies showing no significant difference in UTI recurrence rates between oral cephalosporins and first-line agents 4, 5
• The duration of antibiotic therapy is also important, with short-course antibiotic treatment being at least as effective as longer courses for both microbiological and clinical success in the treatment of acute uncomplicated pyelonephritis 6, 7

Special Considerations

Certain patient populations require special consideration:

• Pregnant patients with pyelonephritis are at significantly elevated risk of severe complications and should be admitted and treated initially with parenteral therapy 3
• Patients with concurrent urinary tract obstruction should be referred for urgent decompression 3
• Patients with sepsis or risk of infection with a multidrug-resistant organism should receive antibiotics with activity against extended-spectrum beta-lactamase-producing organisms 3