Which drug is appropriate for treating uncomplicated pyelonephritis?

Levofloxacin 500 mg is an appropriate choice for treating uncomplicated pyelonephritis due to its effectiveness against the common pathogens associated with this infection, particularly Escherichia coli. As a fluoroquinolone antibiotic, levofloxacin has good penetration into renal tissues and urine, making it particularly suited for urinary tract infections. The higher dosage of 500 mg reflects the need to achieve adequate drug levels in the body to effectively target the bacteria causing the infection, ensuring rapid resolution of symptoms and reducing the risk of complications.

In contrast, the other medications listed may not provide optimal treatment for uncomplicated pyelonephritis. For instance, azithromycin, an antibiotic with activity primarily against atypical pathogens, is not typically used for this kind of infection. Doxycycline, while effective against certain bacteria, lacks the specific effectiveness and tissue penetration needed for pyelonephritis. The lower dose of levofloxacin (250 mg) might not achieve the necessary therapeutic concentrations to effectively treat this condition. Therefore, utilizing levofloxacin at the higher dose is backed by its pharmacokinetics and its spectrum of activity against the usual pathogens encountered in uncomplicated pyelonephritis.