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Polski Merkuriusz Lekarski : Organ... Apr 2013Amiodarone is used to manage virtually all forms of supraventricular and ventricular tachycardia and has therefore become one of the most frequently used antiarrhythmic...
Amiodarone is used to manage virtually all forms of supraventricular and ventricular tachycardia and has therefore become one of the most frequently used antiarrhythmic drugs in clinical practice. Amiodarone has a variable oral bioavailability. After absorption, the drug undergoes extensive enterohepatic circulation. A large first pass effect results in desethylamiodarone, which is active and has similar electrophysiologic effects as the parent compound. Peak amiodarone serum levels, after oral dosing, are achieved within 3-7 hours. Acute amiodarone therapy results in a use-dependent inhibition of inward sodium and inward calcium currents, as well as a non-competitive alpha- and beta-blockade effect. Acute amiodarone therapy has no consistent effects on the repolarization phase of action potentials. The major effect of chronic amiodarone therapy is an inhibition of outward potassium currents resulting in a prolongation of action potential duration, not only in atrial and ventricular muscles but also in the sinoatrial node and atrioventricular nodes. A basic understanding of the pharmacokinetics is important for the clinician to understand the antiarrhythmic properties of both the oral and intravenous preparation.
Topics: Action Potentials; Administration, Oral; Amiodarone; Anti-Arrhythmia Agents; Atrioventricular Node; Evoked Potentials; Humans; Injections, Intravenous; Sinoatrial Node; Tachycardia, Supraventricular; Tachycardia, Ventricular
PubMed: 23745321
DOI: No ID Found -
Circulation Nov 1999
Review
Topics: Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Death, Sudden; Humans; Tachycardia, Ventricular; Ventricular Fibrillation
PubMed: 10556230
DOI: 10.1161/01.cir.100.19.2025 -
Klinische Monatsblatter Fur... Jun 2005Amiodarone, one of the most effective anti-arrhythmic drugs, is also known for its ability to accumulate lipid-pharmakon complexes in the lysosomes of different tissues.... (Review)
Review
Amiodarone, one of the most effective anti-arrhythmic drugs, is also known for its ability to accumulate lipid-pharmakon complexes in the lysosomes of different tissues. In the eye the lysosomal storage leads to typical side-effects. Whorl-like epithelial, reversible corneal inclusions occur in about 70 to 100 % of the patients on amiodarone therapy. Tiny lens opacities without visual impairment have been reported in 50 % of patients who had been treated with amiodarone. At present the most severe complication of amiodarone is optic neuropathy with an incidence of 1.3 to 1.8 %. The optic neuropathy, as the rule, is only reversible approximately in (1/2) of the patients after discontinuing the drug. The fundoscopic picture of amiodarone neuropathy is similar to classic AION. Retinal involvement has also been reported; however, a relationship with amiodarone has not been proven yet.
Topics: Amiodarone; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Corneal Opacity; Dose-Response Relationship, Drug; Eye; Humans; Optic Nerve Diseases; Retinal Degeneration; Risk Assessment; Risk Factors
PubMed: 15973627
DOI: 10.1055/s-2005-858209 -
Progress in Cardiovascular Diseases 1997Amiodarone appears to reduce sudden death in patients with left ventricular dysfunction resulting from an acute MI or a primary dilated cardiomyopathy, particularly if... (Review)
Review
Amiodarone therapy in chronic heart failure and myocardial infarction: a review of the mortality trials with special attention to STAT-CHF and the GESICA trials. Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina.
Amiodarone appears to reduce sudden death in patients with left ventricular dysfunction resulting from an acute MI or a primary dilated cardiomyopathy, particularly if complex ventricular arrhythmias are present. Amiodarone's beneficial effect on mortality in these patients could be unrelated to its antiarrhythmic effects. Multiple factors could account for the improvement in mortality such as the drug's antiischemic effects, neuromodulating effects, its effect on left ventricular function and on heart rate. Moreover, patients with LV dysfunction who have survived an episode of sudden death would potentially benefit from amiodarone therapy. Future trials are needed to determine the precise subsets(s) of patients who would benefit from the drug and the most efficacious dosing regimen for the drug. Based on available data, amiodarone is the only antiarrhythmic agent which has not been shown to increase mortality in patients with chronic heart failure.
Topics: Amiodarone; Clinical Trials as Topic; Death, Sudden, Cardiac; Heart Failure; Hemodynamics; Humans; Myocardial Infarction; Safety; Survival Rate; Treatment Outcome; Vasodilator Agents; Ventricular Dysfunction, Left
PubMed: 9247558
DOI: 10.1016/s0033-0620(97)80025-4 -
Cardioscience Sep 1990One of the potential adverse effects of anti-arrhythmic agents is an impairment of cardiac function as a result of their intrinsic negative inotropic properties.... (Review)
Review
One of the potential adverse effects of anti-arrhythmic agents is an impairment of cardiac function as a result of their intrinsic negative inotropic properties. Amiodarone, in animals, also induces dose-related negative inotropic effects, in addition to coronary and systemic vasodilatation and slowing of the heart. Likewise, in most human studies, intravenous amiodarone gives rise to early systemic and coronary vasodilatation, followed by a reduction in contractility. Depending on the relative impact of these opposing effects on the left ventricle, the changes in heart rate, cardiac output and left ventricular filling pressure are variable. Particularly in patients with pre-existing ventricular dysfunction, cardiac pump function is impaired further when relatively high dosages of amiodarone are used without its solvent Tween 80. In contrast, fast bolus administrations, eg. 5 mg/kg amiodarone in 5 minutes, result in an improvement of cardiac output, albeit at the expense of an increase in left ventricular filling pressure. The latter observation suggests that intravenous amiodarone should be given with caution in patients with heart failure and elevated left ventricular filling pressures. When given by mouth, amiodarone does not have significant hemodynamic effects, other than a moderate reduction in heart rate and, occasionally, in diastolic blood pressure. Cardiac pump function is not affected, even in patients with ventricular dysfunction or heart failure, in whom chronic oral administration of the drug is well tolerated.
Topics: Amiodarone; Animals; Arrhythmias, Cardiac; Dose-Response Relationship, Drug; Heart Failure; Hemodynamics; Humans; Myocardial Contraction; Time Factors; Ventricular Function
PubMed: 2102806
DOI: No ID Found -
Medical Toxicology and Adverse Drug... 1989Amiodarone is an extremely effective antiarrhythmic agent for the treatment of both life-threatening ventricular arrhythmias and refractory supraventricular... (Review)
Review
Amiodarone is an extremely effective antiarrhythmic agent for the treatment of both life-threatening ventricular arrhythmias and refractory supraventricular tachyarrhythmias. Subjective minor side effects are common with amiodarone but rarely require discontinuation of therapy and are often handled by dose reduction. Serious end-organ toxicity, including pulmonary fibrosis and drug-induced hepatitis, have been the most common indications for discontinuing amiodarone therapy in these patients.
Topics: Amiodarone; Animals; Female; Humans; Pregnancy; Teratogens
PubMed: 2671595
DOI: 10.1007/BF03259911 -
Cardiovascular Drug Reviews 2005Dronedarone is a noniodinated benzofuran derivative that has been developed to overcome the limiting iodine-associated adverse effects of the commonly used... (Comparative Study)
Comparative Study Review
Dronedarone is a noniodinated benzofuran derivative that has been developed to overcome the limiting iodine-associated adverse effects of the commonly used antiarrhythmic drug, amiodarone. It displays a wide cellular electrophysiological spectrum largely similar to amiodarone, inhibiting the potassium currents I(Kr), I(Ks), I(KI), I(KACh), and I(sus), as well as sodium currents and L-type calcium currents in isolated cardiomyocytes. In addition, dronedarone exhibits antiadrenergic properties. In vivo, dronedarone has been shown to be more effective than amiodarone in several arrhythmia models, particularly in preventing ischemia- and reperfusion-induced ventricular fibrillation and in reducing mortality. However, an increased incidence of torsades de pointes with dronedarone in dogs shows that possible proarrhythmic effects of dronedarone require further evaluation. The clinical trails DAFNE, EURIDIS, and ADONIS indicated safety, antiarrhythmic efficacy and low proarrhythmic potential of the drug in low-risk patients. In contrast, the increased incidence of death in the dronedarone group of the discontinued ANDROMEDA trial raises safety concerns for patients with congestive heart failure and moderate to severe left ventricular dysfunction. Dronedarone appears to be effective in preventing relapses of atrial fibrillation and atrial flutter. Torsades de pointes, the most severe adverse effect associated with amiodarone, has not yet been reported in humans with dronedarone. Unlike amiodarone, dronedarone had little effect on thyroid function and hormone levels in animal models and had no significant effects on human thyroid function in clinical trials. In conclusion, dronedarone could be a useful drug for prevention of atrial fibrillation and atrial flutter relapses in low-risk patients. However, further experimental studies and long-term clinical trials are required to provide additional evidence of efficacy and safety of dronedarone.
Topics: Amiodarone; Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Atrial Flutter; Dronedarone; Humans; Ion Channels
PubMed: 16252015
DOI: 10.1111/j.1527-3466.2005.tb00167.x -
Acta Ophthalmologica Jun 1983Among 30 patients (17 men, 46-76 years and 13 women, 15-70 years), treated with the antiarrhythmic drug amiodarone, 21 patients (11 men and 10 women) developed bilateral...
Among 30 patients (17 men, 46-76 years and 13 women, 15-70 years), treated with the antiarrhythmic drug amiodarone, 21 patients (11 men and 10 women) developed bilateral cornea verticillata. Total doses up to 494 g had been given and the duration of therapy was up to 113 weeks. In 14 patients samples of 50 microliters tear fluid were analyzed for aminodarone. No amiodarone was present in the tears at low serum concentrations but a rapid increase in tear concentrations was seen at serum values above 1.2 micrograms/ml (P less than 0.001). The grade of cornea verticillata was significantly correlated to total dose as well as to duration of treatment (P less than or equal to 0.001). On the day of examination at the eye clinic there was no significant correlation between se-amiodarone, tear-amiodarone concentration and the grade of cornea verticillata. One patient complained of coloured haloes. None had decreased visual acuity, fundus changes, cataract, exophthalmus, increased intraocular pressure, abnormal colour vision, or abnormal central corneal thickness, which could be attributed to the treatment of amiodarone.
Topics: Adolescent; Adult; Aged; Amiodarone; Benzofurans; Corneal Opacity; Female; Humans; Male; Middle Aged; Tears
PubMed: 6624413
DOI: 10.1111/j.1755-3768.1983.tb01447.x -
Annals of Ophthalmology Aug 1984Amiodarone, 2-N-butyl-3-(4'diethylaminoethoxy-3',5-diiodobenzoyl)benzofuran, also known as Cordarone, is presently under clinical investigation in the United States. It...
Amiodarone, 2-N-butyl-3-(4'diethylaminoethoxy-3',5-diiodobenzoyl)benzofuran, also known as Cordarone, is presently under clinical investigation in the United States. It is an alpha and beta antagonist and is extremely effective in treating otherwise uncontrollable ventricular arrhythmias. To date, 27 patients participating in our ongoing study since 1977 have had corneal deposits. The deposits are in the corneal epithelium basal cell layer, and occur in stages (mild, moderate, and severe), which seem to correlate with dosage and duration of treatment. Vision is rarely diminished by these deposits, and if it is, discontinuation of the drug therapy will cause regression of the deposits with eventual return to normal beginning within two to four weeks but possibly taking as long as 1 1/2 years. The deposits look similar to those seen in chloroquine toxicity and Fabry's glycolipidosis. Other adverse effects reported in the European literature include thyroidopathy, cutaneous pigmentation, and neuromyopathy.
Topics: Amiodarone; Benzofurans; Corneal Diseases; Humans
PubMed: 6497223
DOI: No ID Found -
Iowa Medicine : Journal of the Iowa... Dec 1986
Topics: Amiodarone; Arrhythmias, Cardiac; Humans
PubMed: 3804669
DOI: No ID Found