[Drug-induced arrhythmias].

Arrhythmias could be induced or aggravated by a variety of drugs which include cardiotonic drugs (digitalis, catecholamines, antiarrhythmics), psychiatric drugs (phenothiazines, antidepressants), and potassium losing diuretics. Among these, drugs which would lengthen QT interval and thereby potentially leading to induction of torsade de pointes are clinically important. There exist some predisposing factors which could potentiate proarrhythmic effect of drugs. They include age, congestive heart failure, renal or hepatic dysfunction, electrolyte disturbance (hypokalemia, hypomagnesemia) and previous history of proarrhythmia. It should be, therefore, very cautious when drugs with potentially proarrhythmic effect are given to subjects with predisposing factor(s). Antihistamines, antibiotics or other non-cardiotonic drugs could induce, although rarely, torsade de pointes. Therefore, even a general practitioner should be aware of the proarrhythmic effect of non-cardiotonic drugs.