DRONEDARONE

It has antiarrhythmic properties belonging to all four vaughan-williams classes. It is a multichannel blocker inhibiting the potassium currents, thus prolonging cardiac action potential and refractory periods (Class III). It also inhibits the sodium currents (Class Ib) and the calcium currents (Class IV). It non competitively antagonizes adrenergic activities (Class II).

Indications

Paroxysmal or persistent atrial fibrillation who are in sinus rhythm or who are intended to be cardioverted, to reduce the risk of cardiovascular hospitalization due to atrial fibrillation.

Dosage

oral, 400mg twice a day with meal

Contra-Indications

Permanent atrial fibrillation (Patients in whom normal sinus rhythm will not or cannot be restored), Symptomatic heart failure with recent decompensation requiring hospitalization or NYHA Class IV symptoms, Second-or third- degree atrioventricular (AV) block, or sick sinus syndrome (except when used in conjunction with a functioning pacemaker), Bradycardia 500ms or PR interval > 280 ms, Severe hepatic impairment, Hypersensitivity.

Special Precautions

Paediatrics: safety in less than 18 years not established Pregnancy: Category X; contraindicated Lactation: discontinue breastfeeding or drug Elderly: use with caution in > 75 year old

Side Effects

New or worsening heart failure, liver injury, Pulmonary toxicity, Hypokalemia and Hypomagnesemia with potassium-depleting diuretics, QT prolongation

Drug Interactions

Drugs prolonging the QT interval (inducing Torsade de pointes), Digoxin, Calcium Channel blockers, Beta-blockers, Grape fruit juice.