FDA label d7650c8d-d1d7-48c3-bd72-26acc3c6e922

Amiodarone hydrochloride tablets are intended for use only in patients with the indicated life-threatening arrhythmias because its use is accompanied by substantial toxicity. Amiodarone hydrochloride tablets have several potentially fatal toxicities, the most important of which is pulmonary toxicity (hypersensitivity pneumonitis or interstitial/alveolar pneumonitis) that has resulted in clinically manifest disease at rates as high as 10% to 17% in some series of patients with ventricular arrhythmias given doses around 400 mg/day, and as abnormal diffusion capacity without symptoms in a much higher percentage of patients. Pulmonary toxicity has been fatal about 10% of the time. Liver injury is common with amiodarone hydrochloride tablets, but is usually mild and evidenced only by abnormal liver enzymes. Overt liver disease can occur, however, and has been fatal in a few cases. Like other antiarrhythmics, amiodarone hydrochloride tablets can exacerbate the arrhythmia, e.g., by making the arrhythmia less well tolerated or more difficult to reverse. This has occurred in 2% to 5% of patients in various series, and significant heart block or sinus bradycardia has been seen in 2% to 5%. All of these events should be manageable in the proper clinical setting in most cases. Although the frequency of such proarrhythmic events does not appear greater with amiodarone hydrochloride tablets than with many other agents used in this population, the effects are prolonged when they occur. Even in patients at high risk of arrhythmic death, in whom the toxicity of amiodarone hydrochloride tablets are an acceptable risk, amiodarone hydrochloride tablets pose major management problems that could be life-threatening in a population at risk of sudden death, so that every effort should be made to utilize alternative agents first. The difficulty of using amiodarone hydrochloride tablets effectively and safely itself poses a significant risk to patients. Patients with the indicated arrhythmias must be hospitalized while the loading dose of amiodarone hydrochloride tablets are given and a response generally requires at least one week, usually two or more. Because absorption and elimination are variable, maintenance-dose selection is difficult, and it is not unusual to require dosage decrease or discontinuation of treatment. In a retrospective survey of 192 patients with ventricular tachyarrhythmias, 84 required dose reduction and 18 required at least temporary discontinuation because of adverse effects, and several series have reported 15% to 20% overall frequencies of discontinuation due to adverse reactions. The time at which a previously controlled life-threatening arrhythmia will recur after discontinuation or dose adjustment is unpredictable, ranging from weeks to months. The patient is obviously at great risk during this time and may need prolonged hospitalization. Attempts to substitute other antiarrhythmic agents when amiodarone hydrochloride tablets must be stopped will be made difficult by the gradually, but unpredictably, changing amiodarone body burden. A similar problem exists when amiodarone hydrochloride tablets are not effective; it still poses the risk of an interaction with whatever subsequent treatment is tried.

WARNINGS Amiodarone hydrochloride tablets are intended for use only in patients with the indicated life-threatening arrhythmias because its use is accompanied by substantial toxicity. Amiodarone hydrochloride tablets have several potentially fatal toxicities, the most important of which is pulmonary toxicity (hypersensitivity pneumonitis or interstitial/alveolar pneumonitis) that has resulted in clinically manifest disease at rates as high as 10% to 17% in some series of patients with ventricular arrhythmias given doses around 400 mg/day, and as abnormal diffusion capacity without symptoms in a much higher percentage of patients. Pulmonary toxicity has been fatal about 10% of the time. Liver injury is common with amiodarone hydrochloride tablets, but is usually mild and evidenced only by abnormal liver enzymes. Overt liver disease can occur, however, and has been fatal in a few cases. Like other antiarrhythmics, amiodarone hydrochloride tablets can exacerbate the arrhythmia, e.g., by making the arrhythmia less well tolerated or more difficult to reverse. This has occurred in 2% to 5% of patients in various series, and significant heart block or sinus bradycardia has been seen in 2% to 5%. All of these events should be manageable in the proper clinical setting in most cases. Although the frequency of such proarrhythmic events does not appear greater with amiodarone hydrochloride tablets than with many other agents used in this population, the effects are prolonged when they occur. Even in patients at high risk of arrhythmic death, in whom the toxicity of amiodarone hydrochloride tablets are an acceptable risk, amiodarone hydrochloride tablets pose major management problems that could be life-threatening in a population at risk of sudden death, so that every effort should be made to utilize alternative agents first. The difficulty of using amiodarone hydrochloride tablets effectively and safely itself poses a significant risk to patients. Patients with the indicated arrhythmias must be hospitalized while the loading dose of amiodarone hydrochloride tablets are given and a response generally requires at least one week, usually two or more. Because absorption and elimination are variable, maintenance-dose selection is difficult, and it is not unusual to require dosage decrease or discontinuation of treatment. In a retrospective survey of 192 patients with ventricular tachyarrhythmias, 84 required dose reduction and 18 required at least temporary discontinuation because of adverse effects, and several series have reported 15% to 20% overall frequencies of discontinuation due to adverse reactions. The time at which a previously controlled life-threatening arrhythmia will recur after discontinuation or dose adjustment is unpredictable, ranging from weeks to months. The patient is obviously at great risk during this time and may need prolonged hospitalization. Attempts to substitute other antiarrhythmic agents when amiodarone hydrochloride tablets must be stopped will be made difficult by the gradually, but unpredictably, changing amiodarone body burden. A similar problem exists when amiodarone hydrochloride tablets are not effective; it still poses the risk of an interaction with whatever subsequent treatment is tried.

ADVERSE REACTIONS Adverse reactions have been very common in virtually all series of patients treated with amiodarone hydrochloride tablets for ventricular arrhythmias with relatively large doses of drug (400 mg/day and above), occurring in about three-fourths of all patients and causing discontinuation in 7% to 18%. The most serious reactions are pulmonary toxicity, exacerbation of arrhythmia, and rare serious liver injury (see WARNINGS ), but other adverse effects constitute important problems. They are often reversible with dose reduction or cessation of amiodarone hydrochloride tablet treatment. Most of the adverse effects appear to become more frequent with continued treatment beyond six months, although rates appear to remain relatively constant beyond one year. The time and dose relationships of adverse effects are under continued study. Neurologic problems are extremely common, occurring in 20% to 40% of patients and including malaise and fatigue, tremor and involuntary movements, poor coordination and gait, and peripheral neuropathy; they are rarely a reason to stop therapy and may respond to dose reductions or discontinuation (see PRECAUTIONS ). There have been spontaneous reports of demyelinating polyneuropathy. Gastrointestinal complaints, most commonly nausea, vomiting, constipation and anorexia, occur in about 25% of patients but rarely require discontinuation of drug. These commonly occur during high-dose administration (i.e., loading dose) and usually respond to dose reduction or divided doses. Ophthalmic abnormalities including optic neuropathy and/or optic neuritis, in some cases progressing to permanent blindness, papilledema, corneal degeneration, photosensitivity, eye discomfort, scotoma, lens opacities and macular degeneration have been reported (see WARNINGS ). Asymptomatic corneal microdeposits are present in virtually all adult patients who have been on drug for more than 6 months. Some patients develop eye symptoms of halos, photophobia and dry eyes. Vision is rarely affected and drug discontinuation is rarely needed. Dermatological adverse reactions occur in about 15% of patients, with photosensitivity being most common (about 10%). Sunscreen and protection from sun exposure may be helpful, and drug discontinuation is not usually necessary. Prolonged exposure to amiodarone hydrochloride tablets occasionally results in a blue-gray pigmentation. This is slowly and occasionally incompletely reversible on discontinuation of drug but is of cosmetic importance only. Cardiovascular adverse reactions, other than exacerbation of the arrhythmias, include the uncommon occurrence of congestive heart failure (3%) and bradycardia. Bradycardia usually responds to dosage reduction but may require a pacemaker for control. CHF rarely requires drug discontinuation. Cardiac conduction abnormalities occur infrequently and are reversible on discontinuation of drug. The following side-effect rates are based on a retrospective study of 241 patients treated for 2 to 1,515 days (mean 441.3 days). The following side effects were each reported in 10% to 33% of patients: Gastrointestinal: Nausea and vomiting. The following side effects were each reported in 4% to 9% of patients: Dermatologic: Solar dermatitis/photosensitivity. Neurologic: Malaise and fatigue, tremor/abnormal involuntary movements, lack of coordination, abnormal gait/ataxia, dizziness, paresthesias. Gastrointestinal: Constipation, anorexia. Ophthalmologic: Visual disturbances. Hepatic: Abnormal liver-function tests. Respiratory: Pulmonary inflammation or fibrosis. The following side effects were each reported in 1% to 3% of patients: Thyroid: Hypothyroidism, hyperthyroidism. Neurologic: Decreased libido, insomnia, headache, sleep disturbances. Cardiovascular : Congestive heart failure, cardiac arrhythmias, SA node dysfunction. Gastrointestinal: Abdominal pain. Hepatic: Nonspecific hepatic disorders. Other: Flushing, abnormal taste and smell, edema, abnormal salivation, coagulation abnormalities. The following side effects were each reported in less than 1% of patients: Blue skin discoloration, rash, spontaneous ecchymosis, alopecia, hypotension and cardiac conduction abnormalities. In surveys of almost 5,000 patients treated in open U.S. studies and in published reports of treatment with amiodarone hydrochloride tablets, the adverse reactions most frequently requiring discontinuation of amiodarone hydrochloride tablets included pulmonary infiltrates or fibrosis, paroxysmal ventricular tachycardia, congestive heart failure and elevation of liver enzymes. Other symptoms causing discontinuations less often included visual disturbances, solar dermatitis, blue skin discoloration, hyperthyroidism and hypothyroidism. Post-marketing Reports In post-marketing surveillance, hypotension (sometimes fatal), sinus arrest, anaphylactic/anaphylactoid reaction (including shock), angioedema, urticaria, eosinophilic pneumonia, hepatitis, cholestatic hepatitis, cirrhosis, pancreatitis, renal impairment, renal insufficiency, acute renal failure, bronchospasm, possibly fatal respiratory disorders (including distress, failure, arrest and ARDS), bronchiolitis obliterans organizing pneumonia (possibly fatal), fever, dyspnea, cough, hemoptysis, wheezing, hypoxia, pulmonary infiltrates and/or mass, pulmonary alveolar hemorrhage, pleural effusion, pleuritis, pseudotumor cerebri, parkinsonian symptoms such as akinesia and bradykinesia (sometimes reversible with discontinuation of therapy), syndrome of inappropriate antidiuretic hormone secretion (SIADH), thyroid nodules/thyroid cancer, toxic epidermal necrolysis (sometimes fatal), erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, eczema, skin cancer, vasculitis, pruritus, hemolytic anemia, aplastic anemia, pancytopenia, neutropenia, thrombocytopenia, agranulocytosis, granuloma, myopathy, muscle weakness, rhabdomyolysis, demyelinating polyneuropathy, hallucination, confusional state, disorientation, delirium, epididymitis and impotence, also have been reported with amiodarone therapy.