Summarize the at-risk patient populations for QT-prolonging
INTRODUCTION
An excessive QTc prolongation above 500 msec caused the development of TdP in the
Drugs that prolong the QT interval
62 The antihistamine terfenadine, a potent I Kr blocker that can cause torsade de 1
5
It is unknown whether amiodarone, given to a recipient prior to cardiac transplantation, can cause arrhythmia in a newly transplanted donor heart
4 Amiodarone can prolong the QT interval and is known to cause potentially fatal torsades de pointes (see Precautions)
Before using amiodarone, tell your doctor or Amiodarone is commonly used for the treatment of supraventricular and ventricular arrhythmias
Low thyroid levels (hypothyroidism)—unusual weakness or fatigue, sensitivity to cold, constipation, hair loss, dry skin, weight gain, feelings of depression
Amiodarone, however, can be proarrhythmic and is currently recognized as having a known risk of prolonging QTc and causing TdP
Heart failure has been associated with extended action potentials by blocked IKr channels, leading to an increased risk of drug-induced arrhythmias
Amiodarone was initially developed 3 decades ago for angina
QT間距延長可能引發一種被稱為「Torsade de pointes」的心律不整,這是一種多形性心室心律不整,雖然大部分是自限型的,但可避免還是盡量避免。
Amiodarone is considered to be safe in patients with prior QT prolongation and torsades de pointes taking class I antiarrhythmic agents who require continued antiarrhythmic drug therapy
The observation that not all patients prolong their QT interval after taking macrolides and that even fewer patients experience potentially lethal arrhythmias
inhibited, additive effects) The Sotalol Amiodarone Atrial Fibrillation Efficacy Trial compared the efficacy of sotalol, amiodarone, and placebo in 665 patients with persistent atrial fibrillation
fetilide, ibutilide, and amiodarone, all mar kedly prolong the QT interval