CHF and arrhythmias:
Indications for: NEXTERONE
Initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation (VF) and hemodynamically unstable ventricular tachycardia (VT) in patients refractory to other therapy.
Individualize. First 24hrs: loading infusions: 150mg over the first 10mins (15mg/min) by rapid IV infusion, followed by 360mg over the next 6hrs (1mg/min) by slow IV infusion; and then 540mg over the remaining 18hrs (0.5mg/min) by slow IV infusion. After the first 24hrs: continue maintenance of 720mg per 24hrs (0.5mg/min) by direct infusion. Breakthrough VF or hemodynamically unstable VT: 150mg supplemental infusion over 10mins (15mg/min). Switching to oral amiodarone: see full labeling.
Cardiogenic shock. Marked sinus bradycardia. 2nd- or 3rd-degree AV block unless paced.
Risk of hypotension; monitor initial infusion rate closely and do not exceed recommended rate. Slow infusion rate or discontinue if bradycardia or AV block occurs; may require pacemaker. Monitor for progressive hepatic injury, QTc prolongation during treatment. Correct potassium, magnesium, and calcium deficiencies prior to initiation. Monitor electrolyte and acid-base balance in those with severe or prolonged diarrhea or concomitant diuretics and laxatives. Monitor for new respiratory symptoms and evaluate. Obtain baseline chest X-ray, pulmonary function tests in those to receive amiodarone chronically. Perform ophthalmic exam if changes in visual acuity or decreases in peripheral vision. Monitor thyroid function prior to initiation and periodically thereafter (esp. in the elderly, history of thyroid nodules, goiter, or other thyroid dysfunction). Withdraw cautiously. Elderly. Neonatal injury (monitor). Labor & delivery. Pregnancy (increased risk for fetal toxicity). Nursing mothers: not recommended.
Class III antiarrhythmic.
Interactions may persist months after discontinuing. Increased risk of torsade de pointes with QT prolonging drugs (eg, class I or III antiarrhythmics, lithium, certain phenothiazines, tricyclic antidepressants, certain fluoroquinolones or macrolides, azole antifungals, halogenated inhalation anesthetics); avoid. Potentiated by CYP3A4 inhibitors (eg, certain fluoroquinolones or macrolides, azole antifungals, grapefruit juice, cimetidine); avoid. Potentiates antiarrhythmics (eg, quinidine, procainamide, flecainide); reserve concomitant use for those who are unresponsive to a single agent; reduce their doses by 30–50% for several days after transitioning to oral amiodarone. Potentiates cyclosporine, digoxin (reduce digoxin dose by ½ or discontinue), warfarin (reduce anticoagulant dose by ⅓ to ½ and monitor INR), phenytoin, lidocaine; monitor. Myopathy with statins metabolized by CYP3A4; limit simvastatin dose to 20mg daily or lovastatin dose to 40mg daily. Additive bradycardia, sinus arrest, and AV block with β-blockers, digoxin, verapamil, diltiazem, ivabradine, clonidine; monitor heart rate. Exacerbation of arrhythmias with antiarrhythmics. Symptomatic bradycardia when co-administered with sofosbuvir. Antagonized by St. John’s wort, cholestyramine. May affect thyroid function tests. See full labeling.
Hypotension, asystole/cardiac arrest/pulseless electrical activity, cardiogenic shock, CHF, bradycardia, liver function test abnormalities, VT, AV block; torsade de pointes, thyroid disorders, pulmonary injury, hypersensitivity reactions, phlebitis, vision loss, optic neuropathy/neuritis (reevaluate if occurs).
Generic Drug Availability:
Single-dose container (100mL, 200mL)—1