Question

Which fluoroquinolone has the maximum oral bioavailability?

• A. Moxifloxacin
• B. Gatifloxacin
• C. Levofloxacin
• D. Ciprofloxacin

Hint:

Which quinolone is nearly 100 percent orally bioavailable.

Answer 1

The Correct Option is C

Step 1: Fluoroquinolones as a class are well absorbed after oral dosing, with good oral bioavailability for almost all members except norfloxacin. Step 2: Among the options, levofloxacin has the highest oral bioavailability, reported as close to 100 percent, so an oral dose achieves almost the same exposure as an intravenous dose. Step 3: Ciprofloxacin has notably lower bioavailability (around 70 percent), and moxifloxacin and gatifloxacin, though good, do not reach the near complete absorption of levofloxacin. Step 4: Note that multivalent cations (antacids, iron, calcium) chelate fluoroquinolones and reduce their absorption, similar to tetracyclines. Hence levofloxacin is the correct answer.