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American Journal of Cardiovascular... Dec 2020Amiodarone is an effective antiarrhythmic medication frequently used in practice for both ventricular and atrial arrhythmias. Though classified as a class III... (Review)
Review
Amiodarone is an effective antiarrhythmic medication frequently used in practice for both ventricular and atrial arrhythmias. Though classified as a class III antiarrhythmic, it affects all phases of the cardiac action potential. However, the drug has several side effects, including thyroid abnormalities, pulmonary fibrosis, and transaminitis, for which routine monitoring is recommended. It also interacts with several medications, such as warfarin, simvastatin, and atorvastatin, and many HIV antiretroviral medications. Given the common use of this medication in medical practice, it is vital that clinicians understand the indications, contraindications, dosing, side effects, and interactions of this medication. A thorough understanding of these topics is essential for clinicians to ensure safe and effective use of amiodarone.
Topics: Amiodarone; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Dose-Response Relationship, Drug; Drug Interactions; Humans
PubMed: 32166725
DOI: 10.1007/s40256-020-00401-5 -
Journal of Clinical Pharmacology Nov 1991Amiodarone is a unique antiarrhythmic agent originally developed as a vasodilator. Classified electrophysiologically as a Type III antiarrhythmic, it also has both... (Review)
Review
Amiodarone is a unique antiarrhythmic agent originally developed as a vasodilator. Classified electrophysiologically as a Type III antiarrhythmic, it also has both nonspecific antisympathetic and direct, fast channel-membrane effects. Hemodynamic effects of orally administered amiodarone (a negative inotropic agent) are usually negligible, and are usually compensated for by induced vasodilation. Effects on thyroid and hepatic function may help to explain some of the unique pharmacologic as well as toxicologic effects of the drug. Amiodarone is poorly bioavailable (20-80%) and undergoes extensive enterohepatic circulation before entry into a central compartment. The principal metabolite, mono-n-desethyl amiodarone is also an antiarrhythmic. From this central compartment, it undergoes extensive tissue distribution (exceptionally high tissue/plasma partition coefficients). The distribution half-life of amiodarone out of the central compartment to peripheral and deep tissue compartments (t1/2 alpha) may be as short as 4 hours. The terminal half-life (t1/2 beta) is both long and variable (9-77 days) secondary to the slow mobilization of the lipophilic medication out of (primarily) adipocytes. A pharmacokinetically based loading scheme is described, and data suggesting a role for routine amiodarone plasma levels are presented.
Topics: Administration, Oral; Amiodarone; Arrhythmias, Cardiac; Biological Availability; Hemodynamics; Humans; Metabolic Clearance Rate; Tissue Distribution
PubMed: 1753010
DOI: 10.1002/j.1552-4604.1991.tb03673.x -
Australian and New Zealand Journal of... Nov 1986
Topics: Amiodarone; Anti-Arrhythmia Agents; Biomechanical Phenomena; Corneal Diseases; Dose-Response Relationship, Drug; Humans; Pigmentation Disorders
PubMed: 3814430
DOI: 10.1111/j.1442-9071.1986.tb00479.x -
Archives of Internal Medicine Apr 1987Amiodarone hydrochloride-induced thrombocytopenia seems to be an additional side effect in the course of amiodarone treatment. Two patients with thrombocytopenia during...
Amiodarone hydrochloride-induced thrombocytopenia seems to be an additional side effect in the course of amiodarone treatment. Two patients with thrombocytopenia during amiodarone treatment are described, in whom the diagnosis of amiodarone-induced thrombocytopenia was made by the fact that thrombocytopenia developed during amiodarone treatment and by rechallenge with the drug. Amiodarone-induced thrombocytopenia is probably due to delayed hypersensitivity reaction as indicated by the strongly positive lymphocyte stimulation test results using amiodarone. According to our results, platelet counts should be included in the routine follow-up of patients within the first two weeks after initiation of amiodarone treatment.
Topics: Aged; Amiodarone; Drug Hypersensitivity; Humans; Hypersensitivity, Delayed; Lymphocyte Activation; Male; Middle Aged; Thrombocytopenia
PubMed: 3827461
DOI: No ID Found -
American Journal of Health-system... Mar 2009A case of amiodarone-induced neurotoxicity is reported.
PURPOSE
A case of amiodarone-induced neurotoxicity is reported.
SUMMARY
A 76-year-old man arrived at the emergency department with complaints of increasing imbalance over the past 2.5 months after a recent discharge from the hospital. He reported that his balance had worsened over the past week and that he now must use a cane to walk. His medical history included coronary artery disease, peripheral vascular disease, hypertension, hyperlipidemia, and paroxysmal atrial fibrillation. Home medications included enteric-coated aspirin 325 mg orally daily, isosorbide dinitrate 20 mg orally twice daily, amiodarone hydrochloride 400 mg orally three times daily, hydralazine hydrochloride 10 mg orally four times daily, extended-release metoprolol succinate 142.5 mg (equivalent to metoprolol tartrate 150 mg) orally daily, simvastatin 80 mg orally daily, and warfarin sodium 2.5 mg orally daily. Physical examination of the patient revealed finger-to-nose dysmetria, unsteady gait with leftward prevalence, positive Romberg's sign, and inability to perform heel-to-toe walk. All radiographic imaging studies and laboratory test values ruled out acute pathologies, bleeding, masses, and ischemia. As there were no physiological findings for the patient's symptoms and after careful evaluation of the patient's drug regimen, the patient's amiodarone was discontinued. His ataxia began to slowly improve. All neurologic symptoms resolved completely five months after discontinuation of amiodarone.
CONCLUSION
A 76-year-old man developed ataxia after taking amiodarone hydrochloride 400 mg orally three times daily for more than two months; the regimen was the intended loading dosage. The ataxia lessened over the first two weeks after the amiodarone was discontinued and resolved completely within five months after drug discontinuation.
Topics: Aged; Amiodarone; Ataxia; Humans; Male; Neurotoxicity Syndromes; Postural Balance
PubMed: 19265185
DOI: 10.2146/ajhp080196 -
The New England Journal of Medicine Feb 1987
Review
Topics: Amiodarone; Arrhythmias, Cardiac; Humans; Kinetics
PubMed: 3543680
DOI: 10.1056/NEJM198702193160807 -
Archives of Ophthalmology (Chicago,... Oct 1983Amiodarone hydrochloride is a benzofurane derivative used for cardiac abnormalities. Its use is commonly associated with an asymptomatic keratopathy. Although lipid...
Amiodarone hydrochloride is a benzofurane derivative used for cardiac abnormalities. Its use is commonly associated with an asymptomatic keratopathy. Although lipid deposits have been observed with the electron microscope in the lens epithelium of one patient with a history of amiodarone therapy, lens opacities have not been reported in patients using this drug. Visually inconsequential, anterior subcapsular lens opacities in seven of 14 patients using moderate to high doses of amiodarone who were examined at the Veterans Administration Hospital in San Francisco are reviewed.
Topics: Adult; Aged; Amiodarone; Benzofurans; Cataract; Humans; Male; Middle Aged
PubMed: 6626008
DOI: 10.1001/archopht.1983.01040020556010 -
Archives of Dermatology Dec 1984Amiodarone hydrochloride is currently being investigated in the United States as a cardiac antiarrhythmic agent. Previous reports from Europe indicate that amiodarone...
Amiodarone hydrochloride is currently being investigated in the United States as a cardiac antiarrhythmic agent. Previous reports from Europe indicate that amiodarone occasionally causes a cutaneous photosensitivity reaction that may be associated with a peculiar blue-gray discoloration of the skin. In addition, corneal microdeposits of yellow-brown granules may occur. We report observations on a case of amiodarone photosensitivity and corneal deposits developing in a patient shortly after amiodarone therapy was begun. Symptoms included burning and stinging of the skin, with redness and swelling that developed immediately after sun exposure. Phototesting showed that the photoactivating wavelengths were primarily in the long-wave UV-A spectrum between 350 and 380 nm. Prior application of a 10% dioxybenzone sunscreen greatly reduced the phototest reaction. Four weeks after the patient stopped taking amiodarone, the UV-A sensitivity was still present but diminished, and by ten weeks it had disappeared. During this time, the corneal deposits were reduced in number. All ten patients we have treated so far with amiodarone for cardiac arrhythmias have shown a similar photosensitivity, indicating that this is probably a phototoxic reaction.
Topics: Aged; Amiodarone; Arrhythmias, Cardiac; Benzofurans; Erythema; Humans; Male; Photosensitivity Disorders; Skin; Time Factors; Ultraviolet Rays
PubMed: 6508331
DOI: No ID Found -
British Journal of Clinical Practice.... Apr 1986
Topics: Amiodarone; Benzofurans; Biological Availability; Drug Interactions; Half-Life; Humans; Kinetics; Tissue Distribution
PubMed: 3089248
DOI: No ID Found -
Annals of Internal Medicine Dec 1982Pulmonary toxicity may occur in association with amiodarone hydrochloride therapy. The clinical features of the pulmonary involvement are mild dyspnea, leukocytosis,...
Pulmonary toxicity may occur in association with amiodarone hydrochloride therapy. The clinical features of the pulmonary involvement are mild dyspnea, leukocytosis, hypoxemia, elevation in the erythrocyte sedimentation rate, and restrictive changes on pulmonary function testing. Diffuse interstitial and patchy peripheral alveolar infiltrates, which may frequently involve the upper lobes, characterize the radiologic findings. Accumulation of foamy macrophages in alveolar spaces, hyperplasia of type II pneumocytes, and widening of alveolar septae are noted histologically. Ultrastructural examination shows granular and lamellar membranous structures within distended lysosomes. With cessation of amiodarone therapy and treatment with corticosteroids, clinical symptoms and radiographic abnormalities resolve. The time interval for resolution of radiographic changes appears to be greater than 2 months. The precise role of corticosteroid therapy remains unknown in light of pathologic findings suggesting a metabolic rather than immunologic basis for the toxicity.
Topics: Adult; Aged; Amiodarone; Benzofurans; Dose-Response Relationship, Drug; Glucocorticoids; Humans; Lung; Lung Diseases; Male; Middle Aged; Radiography
PubMed: 7149492
DOI: 10.7326/0003-4819-97-6-839