A patient develops QT prolongation while on a fluoroquinolone. Which member of this class carries the HIGHEST risk of QT prolongation and cardiac arrhythmias?
- A Moxifloxacin ✓
- B Ciprofloxacin
- C Levofloxacin
- D Norfloxacin
Correct answer: A. Moxifloxacin
Explanation
Moxifloxacin (a 4th-generation fluoroquinolone) has the greatest risk of QT prolongation among fluoroquinolones due to its potassium channel blocking properties. Ciprofloxacin and norfloxacin have minimal QT effects. Levofloxacin has an intermediate risk. Moxifloxacin should be avoided in patients with QT prolongation or on other QT-prolonging drugs.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.