Names and pronunciation
(a-mee-oh′da-rone) Corderone , Nexterone, Pacerone
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Drug reference
(a-mee-oh′da-rone) Corderone , Nexterone, Pacerone
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Func. class.: Antidysrhythmic (class III)
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Chem. class.: Iodinated benzofuran derivative
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Do not confuse: amiodarone/amantadine
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ACTION: Prolongs duration of action potential and effective refractory period, noncompetitive α- and β-adrenergic inhibition; increases PR and QT intervals, decreases sinus rate, decreases periph- eral vascular resistance
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USES: Hemodynamically unstable ven- tricular tachycardia, supraventricular tachycardia, ventricular fibrillation not controlled by first-line agents
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Unlabeled uses: Atrial fibrillation treat- ment/prophylaxis, atrial flutter, cardiac arrest, cardiac surgery, CPR, heart fail- ure, PSVT, Wolff-Parkinson-White (WPW) syndrome, supraventricular tachycardia
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CONTRAINDICATIONS: Preg- nancy, breastfeeding, neonates, infants, severe sinus node dysfunction, hypersensi- tivity to this product/iodine/benzyl alco- hol, cardiogenic shock, second- to third- degree AV block, bradycardia Precautions: Children, goiter, Hashimo- to’s thyroiditis, electrolyte imbalances, HF, respiratory disease, torsades de pointes
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Black Box Warning: Hepatotoxicity, car- diac arrhythmias, pneumonitis, pulmonary fibrosis; requires an experienced clinician Black Box Warning: Cardiac dysrhyth- mias: ECG continuously to determine effectiveness; measure PR, QRS, QT intervals; check for PVCs, other dys- rhythmias, B/P continuously for hypo/ hypertension; report dysrhythmias, slowing heart rate; monitor amiodarone level: therapeutic 1-2.5 mcg/mL; toxic >2.5 mcg/mL Black Box Warning: Pulmonary toxic- ity: dyspnea, fatigue, cough, fever, chest pain; product should be discontinued; for ARDS, pulmonary fibrosis, crackles, tachypnea, increased at higher doses (>400 mg/day), toxicity is common, monitor chest x-ray, PFTs with diffusion capacity • Stevens-Johnson syndrome: monitor for rash, blistering; discontinue immedi- ately, notify prescriber Black Box Warning: Hepatotoxicity: monitor hepatic enzymes; rarely fatal hepatotoxicity has occurred • Electrolytes (sodium, potassium, chloride); hepatic studies: AST, ALT, bilirubin, alkaline phosphatase; for de- hydration, hypovolemia; monitor PT, INR if using warfarin • CNS symptoms: confusion, psychosis, A numbness, depression, involuntary movements; product should be discontin- ued • Hypothyroidism: lethargy; dizziness; constipation; enlarged thyroid gland; edema of extremities; cool, pale skin • Hyperthyroidism: restlessness; tachy- cardia; eyelid puffiness; weight loss; fre- quent urination; menstrual irregularities; dyspnea; warm, moist skin; may cause fatal thyrotoxicosis, cardiac dysrhythmias; may need to discontinue product • Ophthalmic exams at baseline and pe- riodically (PO); to prevent corneal de- posits, use methylcellulose • Cardiac rate, respirations: rate, rhythm, character, chest pain; start with patient hospitalized and monitored up to 1 wk; for rebound hypertension after 1-2 hr • Beers: Avoid as first-line therapy for atrial fibrillation in older adults unless heart failure or substantial left ventricu- lar hypertrophy is present
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SIDE EFFECTS CNS: Headache, dizziness, involuntary movement, tremors, peripheral neuropathy, malaise, fatigue, ataxia, paresthesias, insomnia, confusion, hallucinations CV: Hypotension, bradycardia, HF, dysrhythmias EENT: Corneal microdeposits, dry eyes ENDO: Hypo/hyperthyroidism GI: Nausea, vomiting, diarrhea, abdom- inal pain, anorexia, constipation, hepa- totoxicity, pancreatitis GU: Epididymitis, ED INTEG: Rash, photosensitivity, blue- gray skin discoloration, alopecia, spontaneous ecchymosis, toxic epider- mal necrolysis, urticaria, pancreati- tis, phlebitis (IV) MISC: Flushing, abnormal taste or smell, edema, abnormal salivation RESP: Pulmonary fibrosis/toxicity, ARDS
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INTERACTIONS Increase: QT prolongation—azoles, fluo- roquinolones, macrolides, loratadine, traZODone Increase: amiodarone concentrations, possible serious dysrhythmias—protease inhibitors; reduce dose Increase: myopathy—HMG-CoA reduc- tase inhibitors; monitor for myopathy Increase: bradycardia, sinus arrest, AV block—β-blockers, calcium channel blockers; use cautiously Increase: levels of cycloSPORINE, dex- tromethorphan, digoxin, disopyramide, flecainide, methotrexate, phenytoin, pro- cainamide, quiNIDine, theophylline, class I antidysrhythmics Increase: anticoagulant effects—dabiga- tran, warfarin, dose may need to be decreased (warfarin) Drug/Herb • St. John’s wort may decrease amioda- rone level Drug/Food • Toxicity: grapefruit juice Drug/Lab Test Increase: T4, ALT, AST, GGT alkaline phosphatase, cholesterol, lipids, PT, INR Decrease: T3
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TREATMENT OF OVERDOSE: O2, artificial ventilation, ECG, administer DOPamine for circulatory depression, administer diazePAM, thiopental for sei- zures, isoproterenol
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DOSAGE AND ROUTES Ventricular dysrhythmias Adult: PO Loading dose 800-1600 mg/ day for 1-3 wk, then 600-800 mg/day for 1 mo, maintenance 400 mg/day; IV load- ing dose (first rapid) 150 mg over the first 10 min, then slow 360 mg over the next 6 hr, maintenance 540 mg given over the remaining 18 hr, decrease rate of the slow infusion to 0.5 mg/min Supraventricular tachycardia • Adult: PO 600-800 mg/day × 1 wk until desired response, then decrease to 400 mg/day × 3 wk, then 200-400 mg/ day (maintenance) • Child: PO 10 mg/kg/day × 10 days or until desired response, then decrease to 5 mg/kg/day for several weeks, then de- crease to 2.5 mg/kg/day or lower (main- tenance) Conversion of atrial fibrillation to sinus rhythm (unlabeled) • Adult: IV 5-7 mg/kg over 30-60 min, then 1.2-1.8 mg/kg CONTINUOUS IV INFUSION or PO divided doses
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Available forms: Tablets 100, 200, 400 mg; injection 50 mg/mL
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Administer: PO route • May be used with/without food but be consistent IV, direct route • Peripheral: max 2 mg/mL for more than 1 hr; preferred through central venous line with in-line filter; concentra- tions of more than 2 mg/mL should be given by central line • Cardiac arrest: give 300 mg IV bolus; diluted to a total volume of 20 mL D5W; may repeat 150 mg after 3-5 min Intermittent IV INFUSION route • Rapid loading: add 3 mL (150 mg), 100 mL D5W (1.5 mg/mL), give over 10 min • Slow loading: add 18 mL (900 mg), 500 mL D5W (1.8 mg/mL), give over next 6 hr Continuous IV INFUSION route • After 24 hr, dilute 50 mL to 1-6 mg/ mL, give 1-6 mg/mL at 1 mg/min for the first 6 hr, then 0.5 mg/min Y-site compatibilities: Amikacin, clindamy cin, DOBUTamine, DOPamine, doxycycline, erythromycin, esmolol, gentamicin, insulin, isoproterenol, labetalol, lidocaine, meta- raminol, metroNIDAZOLE, midazolam, morphine, nitroglycerin, norepinephrine, penicillin G potassium, phenylephrine, po- tassium chloride, procainamide, tobramy- cin, vancomycin
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Assess:
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Evaluate: • Therapeutic response: decrease in ventricular tachycardia, supraventricular tachycardia, fibrillation
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To take this product as directed; to avoid missed doses; not to use with grape- fruit juice; not to discontinue abruptly, not to use other drugs, herbs without pre- scriber approval, many interactions • To use sunscreen or stay out of sun to prevent burns; that dark glasses may be needed for photophobia • To report side effects immediately; more common at high dose and longer duration • That skin discoloration is usually re- versible • To report vision changes, weight change, rash, blistering, numbness, tem- perature intolerance • Pregnancy/breastfeeding: Identify if pregnancy is planned or suspected or if breastfeeding; not to be used in preg- nancy, breastfeeding
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PHARMACOKINETICS PO: Onset 1-3 wk, peak 3-7 hr; IV: Onset 2 hr, peak 3-7 hr; half-life 26-107 days, increased in geriatric patients, metabolized by liver (an inhibitor of CYP1A2, CYP3A4, CYP2C8, CYP2C9, CYP2C19, CYP2A6, CYP2B6, CYP2D6, P-glycoprotein), excreted by kidneys, 99% protein binding
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• Adult: PO 600-800 mg/day × 1 wk until desired response, then decrease to 400 mg/day × 3 wk, then 200-400 mg/ day (maintenance)
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• Child: PO 10 mg/kg/day × 10 days or until desired response, then decrease to 5 mg/kg/day for several weeks, then de- crease to 2.5 mg/kg/day or lower (main- tenance) Conversion of atrial fibrillation to sinus rhythm (unlabeled)
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• Adult: IV 5-7 mg/kg over 30-60 min, then 1.2-1.8 mg/kg CONTINUOUS IV INFUSION or PO divided doses
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