Amiodarone

[Guest guest]

Ok, I got a response from Dr. Brownstein. His words were: BIG BIG Risks. Dangerous Drug. Associated with a Ton of bad things. "This is" No way to get Iodine.

So if you think it is better than no iodine at all. Think again. You would be better off w/o both if you only have the option of Amiodarone.

This is from the PDR:

CORDARONE

RX Amiodarone HCl (Wyeth)

THERAPEUTIC CLASS Class III antiarrhythmic

INDICATIONS Back to top Treatment of documented, life-threatening recurrent ventricular fibrillation and recurrent hemodynamically unstable ventricular tachycardia.

ADULT DOSAGE Back to top Adults: Give LD in hospital. LD: 800-1600mg/day in divided doses for 1-3 weeks. After control is achieved, then 600-800mg/day for 1 month. Maint: 400mg/day; up to 600mg/day if needed. Use lowest effective dose. Take with meals. Elderly: Start at low end of dosing range.

HOW SUPPLIED Back to top Tab: 200mg* *scored

CONTRAINDICATIONS Back to top Severe sinus-node dysfunction causing marked sinus bradycardia; 2nd- and 3rd-degree AV block; when episodes of bradycardia have caused syncope (except when used with a pacemaker); cardiogenic shock. Hypersensitivity to iodine.

WARNINGS/PRECAUTIONS Back to top Only for life-threatening arrhythmias due to its substantial toxicity (eg, pulmonary toxicity including pulmonary alveolar hemorrhage, hepatic injury, arrhythmia exacerbation). Hospitalize when giving LD. May cause a clinical syndrome of cough and progressive dyspnea. D/C if LFTs are 3x ULN or if elevated baseline doubles; monitor LFTs regularly. Optic neuropathy, optic neuritis reported. Fetal harm in pregnancy. May develop reversible corneal micro deposits (eg, visual halos, blurred vision), photosensitivity, peripheral neuropathy (rare). May decrease T3 levels, increase thyroxine levels, increase inactive reverse T3 levels and can cause hypo- or hyperthyroidism. Hyperthyroidism may result in thyrotoxicosis and/or the possibility of arrhythmia breakthrough or aggravation. ARDS reported with surgery. Correct K+ or magnesium deficiency before therapy. Caution in elderly.

ADVERSE REACTIONS Back to top Pulmonary toxicity (eg, inflammation, fibrosis), arrhythmia exacerbation, hepatic injury, malaise, fatigue, tremor, poor coordination, paresthesis, nausea, vomiting, constipation, anorexia, ophthalmic abnormalities, photosensitivity, akinesia, bradykinesia.

DRUG INTERACTIONS Back to top Risk of interactions after discontinuation due to its long half-life. May increase sensitivity to myocardial depressant and conduction effects of halogenated inhalation anesthetics. Elevates cyclosporine plasma levels. D/C or reduce digoxin dose by 50%. D/C or decrease warfarin dose by 1/3-1/2. Avoid grapefruit juice. Caution with β-blockers, CCBs, lidocaine, methotrexate. May increase levels of quinidine, procainamide, phenytoin, flecainide. Initiate added antiarrhythmic drug at lower than usual dose. D/C or decrease quinidine dose by 1/3-1/2. D/C or decrease procainamide dose by 1/3. Caution with loratadine, trazadone, disopyramide, fluoroquinolones, macrolides, azoles; QT prolongation reported. Decreased levels with cholestyramine, rifampin, phenytoin, St. 's wort. Rhabdomyolysis/myopathy reported with HMG-CoA reductase inhibitors (simvastatin and atorvastatin). Ineffective inhibition of platelet aggregation with clopidogrel. Fentanyl may cause hypotension, bradycardia, and decreased cardiac output. Increased levels with protease inhibitors; monitor for toxicity. Increased levels of CYP1A2, CYP2C9, CYP2D6, CYP3A4 substrates reported. Interactions reported with CYP3A4 inducers. CYP2C8 and CYP3A4 inhibitors may increase amiodarone levels.

PREGNANCY Back to top Category D, not for use in nursing.

MECHANISM OF ACTION Back to top Class III antiarrhythmic; prolongs myocardial cell-action potential duration and refractory period, and causes noncompetitive α- and β-adrenergic inhibition.

PHARMACOKINETICS Back to top Absorption: Slow and variable; Tmax=3-7 hrs. Distribution: Vd=60L/kg; plasma protein binding (96%); found in breast milk. Metabolism: CYP3A4, 2C8; desethylamiodarone (major metabolite). Elimination: Bile, urine; T1/2=58 days, 36 days (metabolite).

ASSESSMENT Back to top Assess for life threatening arrhythmias, ventricular arrhythmia, optic neuropathy or optic neuritis, hepatic impairment, pregnancy/nursing status, thyroid function, pre-exsisting pulmonary disease, recent MI, and possible drug interactions. Correct hypokalemia and hypomagnesemia prior to initiation.

MONITORING Back to top Monitor for pulmonary toxicities (eg, hypersensitivity pneumonitis, or interstitial/alveolar pneumonitis) manifested by cough, progressive dyspnea, and fatalities, accompanied by functional, radiological, gallium-scan, and pathological data. Perform history, physical exam, and chest X-ray every 3-6 months. Monitor for sinus bradycardia, sinus arrest, and heart block. Monitor induced hyperthyroidism/thyrotoxicosis, hepatic failure, optic neuritis/neuropathy, corneal microdeposits, vision loss, fetal harm, peripheral neuropathy, photosensitivity, LFTs, T4, T3 and reverse T3. Perioperative monitoring for hypotension and ARDS recommended.

PATIENT COUNSELING Back to top Advise to notify physician if pregnant/nursing. Inform about benefits/risks, including possibility of vision impairment, thyroid abnormalities, peripheral neuropathy, and photosensitivity. Report any adverse reactions to physician. Counsel to take as directed. Do not take with grapefruit juice. Avoid prolonged sunlight exposure. Advise that corneal refractive laser surgery is contraindicated with concurrent use.

ADMINISTRATION/STORAGE Back to top Administration: Oral route. Storage: 20-25°C (68-77°F). Protect from light.