Female preponderance in ibutilide-induced torsade de pointes.
OBJECTIVE
Ibutilide, a class III antiarrhythmic agent used for pharmacological cardioversion of atrial arrhythmias, has a potential to cause QT-interval prolongation and torsade de pointes. Purpose of this study was to determine whether women are more prone to develop ibutilide-induced torsade de pointes.


METHODS
All clinical trials, cases, case series, and related articles in English-language in addition to 51 patients from our institution on the subject were examined.


RESULTS
In a database derived from 23 reports in literature and from our institution, 1720 patients received ibutilide for cardioversion of atrial arrhythmias. Only in 87% (n=1492) patients, data were reported whether or not ibutilide caused torsade de pointes. The overall incidence of torsade de pointes was 3.9% (n=58) patients. Data on sex distribution of ibutilide-induced torsade de pointes was available in 73% (n=1096) patients. Torsade de pointes developed in 17 (5.6%) of 304 women and 24 (3%) of 792 men (P=0.05). It occurred during or within 45 min after completion of the infusion of ibutilide. Treatment instituted was with intravenous magnesium sulfate alone in 14% (n=8) patients, magnesium sulfate plus lidocaine in 5% (n=3) patients, magnesium sulfate with electrical cardioversion in 17% (n=10) patients, electrical cardioversion alone in 19% (n=11) patients, and precordial thump in 3% (n=2) patients. In 41% (n=24) of patients who developed torsade de pointes, it resolved without treatment. There were no reported deaths secondary to torsade de pointes associated with ibutilide infusion.


CONCLUSIONS
Incidence of ibutilide-induced torsade de pointes is higher in women than in men. Greater caution must be observed while using ibutilide in women.
Gowda
Ramesh M
RM
Division of Cardiology, Long Island College Hospital, Brooklyn, NY, USA.
Khan
Ijaz A
IA
Punukollu
Gopikrishna
G
Vasavada
Balendu C
BC
Sacchi
Terrence J
TJ
Wilbur
Sabrina L
SL
D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D017678:Sex Distribution; D013449:Sulfonamides / Q000009:adverse effects*; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000453:epidemiology*
D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide