A 45-year-old man presents with flank pain and a febrile urinary tract infection caused by a ciprofloxacin-susceptible Escherichia coli. Which rationale best supports selecting ciprofloxacin for outpatient therapy in this case?

• A. Ciprofloxacin achieves high urinary and tissue concentrations, is broad-spectrum against gram-negative uropathogens including E. coli, and is appropriate for complicated or pyelonephritis-type infections when susceptibility is confirmed.
• B. Ciprofloxacin is ineffective in urinary infections because it is not excreted in the urine and therefore cannot reach therapeutic concentrations at the site of infection.
• C. Ciprofloxacin is bacteriostatic against E. coli and therefore is preferred for all uncomplicated cystitis cases because it avoids rapid bacterial killing that could cause excessive inflammation.
• D. Ciprofloxacin only treats gram-positive organisms effectively and therefore should be combined with an aminoglycoside to cover gram-negative uropathogens.

Answer: (A)