American Board of Internal Medicine (ABIM) Certification Practice Exam

Which medication should patients with acute pyelonephritis who do not require hospitalization begin treatment with?

1. An intravenous cephalosporin

2. An oral fluoroquinolone

3. An oral aminoglycoside

4. An oral beta-lactam

The correct answer is: An oral fluoroquinolone

In cases of acute pyelonephritis for patients who can be managed on an outpatient basis, starting treatment with an oral fluoroquinolone is an appropriate choice. Fluoroquinolones, such as ciprofloxacin or levofloxacin, have broad-spectrum activity against the most common pathogens that cause urinary tract infections, including Escherichia coli. Their oral bioavailability allows for effective treatment without the need for intravenous administration, which is beneficial for patients who do not require hospitalization. Fluoroquinolones also penetrate well into the renal parenchyma and urine, making them effective in treating kidney infections. This attribute is particularly important in acute pyelonephritis, where infection is located in the kidneys rather than just the bladder. The other options may not be as appropriate for outpatient management. Intravenous cephalosporins are typically reserved for patients who require hospitalization, as they do not provide an oral alternative. Oral aminoglycosides are less commonly used due to their dosing schedules and potential nephrotoxicity, as well as being less effective for outpatient treatment compared to fluoroquinolones. While oral beta-lactams can be useful in some urinary tract infections, they generally have a narrower spectrum of