Dronedarone is a benzofuran derivative that is structurally similar to amiodarone without the iodine substituent. Like amiodarone, it exhibits the antiarrhythmic properties of all four Vaughan-Williams classification drugs. Multaq (dronedarone, dronedarone) Tablets Instructions for Use (FDA approved in 09) I. Indications: Dronedarone is an antiarrhythmic drug indicated for patients with paroxysmal or persistent atrial fibrillation (AF) to reduce the risk of hospitalization. Dosage and Administration Dosage and Administration: 1 tablet of 400 mg twice daily, one in the morning and one in the evening. Contraindications: 1. Heart failure category IV or recent decompensated symptomatic heart failure; 2. II- or III-degree atrioventricular (AV) block or sick sinus node syndrome (except with functional pacemakers); 3. Bradycardia <50 bpm; 4. Concomitant use of strong CYP3A inhibitors; 5. Concomitant use of drugs and herbs that prolong the QT interval and can induce tip-twisting ventricular tachycardia (Torsade de Pointes); 6. QTc Bazett interval ≥ 500 ms; 7. Severe liver injury; 8. Pregnancy; 9. Nursing mothers. The instructions already contain a black box warning against the use of the drug in patients with NYHA class IV heart failure or who have recently experienced decompensation requiring hospitalization. This warning is based on the results of the ANDROMEDA study, another prematurely discontinued study of dronedarone, which found increased mortality in such patients in the dronedarone treatment group compared to the placebo control group. In the PALLAS study (the Outcomes Study of Permanent Atrial Fibrillation Treated with Dronedarone in Addition to Standard Therapy), a significant increase in cardiovascular events in patients with permanent atrial fibrillation treated with dronedarone led the drug's manufacturer to suspend the Phase IIIb study.