Torsade de pointes associated with moxifloxacin: a rare but potentially fatal adverse event

Abstract

Torsade de pointes occuring due to a long QT interval is a rare but potentially fatal arrhythmia. Acquired long QT develops most commonly because of drugs that prolong ventricular repolarization. It has been reported that fluoroquinolone antimicrobials prolong the corrected QT interval but rarely cause torsade de pointes. A patient with torsade de pointes risk factors (female sex, advanced age, extreme bradycardia and renal failure) who developed the condition on the fourth day of 400 mg/day of oral moxifloxacin treatment is presented. After the moxifloxacin was stopped, the corrected QT interval normalized and a permanent cardiac pacemaker was implanted. During 11 months of follow-up, arrhythmia did not recur.

Figures

Figure 1)

The electrocardiogram of the patient at admission. A junctional rhythm with a rate of 30 beats/min is seen. The QT interval was 0.66 s and the corrected QT interval was 0.47 s (the paper speed was 25 mm/s)

Figure 2)

Telemetry record showing torsade de pointes that terminated spontaneously after 36 s. A short-long-short sequence preceded the arrhythmia (the paper speed was 25 mm/s)