Moxifloxacin and torsade de pointes

Area of Science:

• Cardiology
• Pharmacology
• Infectious Diseases

Background:

• Moxifloxacin is a fluoroquinolone antibiotic commonly used for bacterial infections.
• Fluoroquinolones are known to carry a risk of QTc interval prolongation and associated arrhythmias.
• Limited data exists specifically linking moxifloxacin to torsade de pointes.

Observation:

• An 87-year-old female patient developed torsade de pointes 8-10 hours after initiating intravenous moxifloxacin for pneumonia.
• The patient exhibited significant QTc interval prolongation two hours post-moxifloxacin administration.
• The arrhythmia resolved spontaneously after a precordial thump, and the QTc interval normalized after moxifloxacin discontinuation.

Findings:

• The case suggests a probable causal relationship between intravenous moxifloxacin and the development of torsade de pointes.
• The Naranjo probability scale indicated a probable association between the event and moxifloxacin.
• Underlying risk factors for prolonged QT interval may predispose patients to this adverse event.

Implications:

• Clinicians should exercise caution when prescribing moxifloxacin to patients with risk factors for QT interval prolongation.
• Judicious administration and close monitoring for cardiac events are recommended in such patients.
• This case highlights the potential for moxifloxacin to trigger life-threatening arrhythmias in susceptible individuals.