Nexterone

5 WARNINGS AND PRECAUTIONS • Hypotension: Slow the infusion; as needed, add vasopressor drugs, positive inotropic agents, and volume expansion. (5.2) • Bradycardia and AV block: Slow the infusion or discontinue. ( 5.3 ) 5.1 Persistence of Adverse Effects Because of the long half-life of amiodarone (9 to 36 days) and its metabolite desethylamiodarone (9 to 30 days), adverse reactions or interactions, as well as observed adverse effects, can persist following amiodarone withdrawal. 5.2 Hypotension Hypotension, the most common adverse reaction seen with intravenous amiodarone seen most often in the first several hours of treatment and is likely related to the rate of infusion. In some cases, hypotension may be refractory and result in a fatal outcome. Hypotension necessitating alterations in intravenous amiodarone therapy was reported in 3% of patients, with permanent discontinuation required in less than 2% of patients. Treat hypotension initially by slowing the infusion; additional standard therapy may be needed, including the following: vasopressor drugs, positive inotropic agents, and volume expansion . Monitor the initial rate of infusion closely and do not exceed the recommended rate [ see Dosage and Administration (2) ]. 5.3 Bradycardia and Atrioventricular Block NEXTERONE causes bradycardia and AV block which may require slowing the infusion rate or discontinuing NEXTERONE. In some patients, inserting a pacemaker is required. Have a temporary pacemaker available when treating a patient predisposed to bradycardia or AV block. 5.4 Hepatic Injury Acute hepatocellular necrosis leading to hepatic coma, acute renal failure, and death has been associated with the administration of intravenous amiodarone. Intravenous infusions at much higher concentrations and rates of infusion than those recommended appear to increase this risk [ see Dosage and Administration (2) ]. Carefully monitor patients receiving NEXTERONE for evidence of progressive hepatic injury. Consider reducing the rate of administration or withdrawing NEXTERONE if hepatic injury occurs. 5.5 Proarrhythmia NEXTERONE may cause a worsening of existing arrhythmias or precipitate a new arrhythmia, sometimes leading to fatal outcomes [ see Adverse Reactions (6.2) ]. Proarrhythmia, primarily torsade de pointes (TdP), has been associated with prolongation, by intravenous amiodarone. Although QTc prolongation occurred frequently in patients receiving intravenous amiodarone, TdP or new-onset VF occurred infrequently (less than 2%). Monitor patients for QTc prolongation during infusion with NEXTERONE. Reserve the combination of amiodarone with other antiarrhythmic therapies that prolong the QTc to patients with life-threatening ventricular arrhythmias who are incompletely responsive to a single agent. Correct hypokalemia, hypomagnesemia or hypocalcemia whenever possible before initiating treatment with NEXTERONE, as these disorders can exaggerate the degree of QTc prolongation and increase the potential for TdP. Give special attention to electrolyte and acid-base balance in patients experiencing severe or prolonged diarrhea or in patients receiving concomitant diuretics and laxatives. 5.6 Pulmonary Injury Early-onset Pulmonary Toxicity There have been postmarketing reports of acute-onset (days to weeks) pulmonary injury in patients treated with intravenous amiodarone. Findings have included pulmonary infiltrates and masses on X-ray, pulmonary fibrosis, bronchospasm, wheezing, fever, dyspnea, cough, hemoptysis, and hypoxia. Two percent (2%) of patients were reported to have adult respiratory distress syndrome (ARDS) during clinical studies involving 48 hours of therapy. Some cases have progressed to respiratory failure or death. Monitor for new respiratory symptoms and evaluate appropriately. Obtain a baseline chest X-ray and pulmonary function tests in patients who are expected to be receiving amiodarone chronically. 5.7 Loss of Vision Cases of optic neuropathy and optic neuritis, usually resulting in visual impairment, have been reported in patients treated with oral amiodarone or intravenous amiodarone. In some cases, visual impairment has progressed to permanent blindness. Optic neuropathy and neuritis may occur at any time following initiation of therapy. Perform an ophthalmic examination if symptoms of visual impairment appear, such as changes in visual acuity and decreases in peripheral vision. Re-evaluate the necessity of amiodarone therapy if optic neuropathy or neuritis is suspected. 5.8 Thyroid Abnormalities Nexterone inhibits peripheral conversion of throxine (T4) to triiodothyronine (T3) and may cause increased T3 levels, and increased levels of inactive reverse T3 (rT3) in clinically euthyroid patients. Monitor thyroid function prior to treatment and periodically thereafter, particularly in elderly patients, and in any patient with a history of thyroid nodules, goiter, or other thyroid dysfunction. Hyperthyroidism may induce arrhythmia breakthrough. If any new signs of arrhythmia appear, the possibility of hyperthyroidism should be considered. Antithyroid drugs, β-adrenergic blockers, temporary corticosteroid therapy may be necessary to treat the symptoms of hyperthyroidism. The action of antithyroid drugs may be delayed in amiodarone-induced thyrotoxicosis because of substantial quantities of preformed thyroid hormones stored in the gland. Radioactive iodine therapy is contraindicated because of the low radioiodine uptake associated with amiodarone-induced hyperthyroidism. Nexterone-induced hyperthyroidism may be followed by a transient period of hypothyroidism. In some clinically hypothyroid amiodarone-treated patients, free thyroxine index values may be normal. Manage hypothyroidism by reducing the dose of or discontinuing amiodarone and thyroid hormone supplementation. 5.9 Neonatal Injury Amiodarone can cause fetal harm when administered to a pregnant woman. Fetal exposure may increase the potential for adverse experiences including cardiac, thyroid, neurodevelopmental, neurological and growth effects in neonate. Inform the patient of the potential hazard to the fetus if NEXTERONE is administered during pregnancy or if the patient becomes pregnant while taking NEXTERONE [ see Pregnancy (8.1) ]. 5.10 Hypersensitivity Reactions Anaphylactic/anaphylactoid reactions have been reported with intravenous amiodarone including shock (sometimes fatal), cardiac arrest, and the following manifestations: hypotension, tachycardia, hypoxia, cyanosis, rash, Stevens-Johnson syndrome, flushing, hyperhidrosis and cold sweat. 5.11 Phlebitis Infusion site phlebitis has occurred in patients receiving intravenous amiodarone. Intravenous amiodarone concentrations greater than 3 mg/mL have been associated with a high incidence of peripheral vein phlebitis.

6 ADVERSE REACTIONS The following adverse reactions are described elsewhere in labeling: • Hypotension [ see Warnings and Precautions (5.2) ] • Hepatic injury [ see Warnings and Precautions (5.4) ] • Proarrhythmia [ see Warnings and Precautions (5.5) ] • Pulmonary injury [ see Warnings and Precautions (5.6) ] • Thyroid injury [ see Warnings and Precautions (5.8) ] • Hypersensitivity [ see Warnings and Precautions (5.10) ] • The most common adverse reactions (1-2%) leading to discontinuation of intravenous amiodarone therapy are hypotension, asystole/cardiac arrest/pulseless electrical activity, VT, and cardiogenic shock. (6) • Other important adverse reactions are torsade de pointes, congestive heart failure, and liver function test abnormalities. (6) To report SUSPECTED ADVERSE REACTIONS, contact Baxter Healthcare at 1-866-888-2472 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In a total of 1836 patients in controlled and uncontrolled clinical trials, 14% of patients received intravenous amiodarone for at least one week, 5% received it for at least 2 weeks, 2% received it for at least 3 weeks, and 1% received it for more than 3 weeks. The mean duration of therapy in these studies was 5.6 days; median exposure was 3.7 days. The most important adverse reactions were hypotension, asystole/cardiac arrest/pulseless electrical activity (PEA), cardiogenic shock, congestive heart failure, bradycardia, liver function test abnormalities, VT, and AV block. Overall, treatment was discontinued for about 9% of the patients because of adverse reactions. The most common adverse reactions leading to discontinuation of intravenous amiodarone therapy were hypotension (1.6%), asystole/cardiac arrest/PEA (1.2%), VT (1.1%), and cardiogenic shock (1%). Other adverse reactions reported in less than 2% of patients receiving intravenous amiodarone in controlled and uncontrolled studies included the following: abnormal kidney function, diarrhea, shock, sinus bradycardia, Stevens-Johnson syndrome, VF, and vomiting. 6.2 Post-Marketing Experience The following adverse reactions have been reported in the post-marketing experience during or in close temporal relationship to intravenous amiodarone administration. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic System Disorders: pancytopenia, neutropenia, hemolytic anemia, aplastic anemia, thrombocytopenia, and granulocytosis. Cardiac Disorders: sinus node dysfunction (sinus arrest, sinoatrial block), intraventricular conduction disorders including bundle branch block and infra-HIS block, bradycardia (sometimes fatal), ventricular extrasystoles, and antegrade conduction via an accessory pathway. Endocrine Disorders: syndrome of inappropriate antidiuretic hormone secretion (SIADH). Eye Disorders: visual field defect and blurred vision. Gastrointestinal Disorders: pancreatitis. General Disorders and Administration Site Conditions: infusion site reactions, including thombosis, phlebitis, thrombophlebitis, cellulitis, pain, induration, edema, inflammation, urticaria, pruritus, erythema, pigment changes, hypoesthesia, skin sloughing, extravasation possibly leading to venous/infusion site necrosis, and granuloma. Hepatobiliary Disorders: cholestasis, cirrhosis, jaundice, alkaline phosphatase and blood lactate dehydrogenase increase. Musculoskeletal and Connective Tissue Disorders: myopathy, muscle weakness, rhabdomyolysis, muscle spasms, and back pain. Neoplasms benign, malignant and unspecified (incl cysts and polyps) Disorders: thyroid nodules/thyroid cancer. Nervous System Disorders: intracranial pressure increased, pseudotumor cerebri, tremor, dizziness and hypoesthesia. Psychiatric Disorders: confusional state, hallucination, disorientation, and delirium. Renal and Urinary Disorders: acute renal failure (sometimes fatal), renal impairment, renal insufficiency, and blood creatinine increased. Reproductive Disorders and Breast Disorders: Epididymitis Respiratory, Thoracic and Mediastinal Disorders: interstitial pneumonitis, bronchiolitis obliterans organizing pneumonia (possibly fatal), pulmonary alveolar hemorrhage, pulmonary phospholipidoisis, pleural effusion, bronchospasm, dyspnea, cough, hemoptysis, wheezing, and hypoxia. Skin and Subcutaneous Tissue Disorders: toxic epidermal necrolysis (sometimes fatal), Stevens-Johnson syndrome, exfoliative dermatitis, erythema multiforme, skin cancer, pruritus, angioedema, and urticaria. Vascular Disorders: vasculitis and flushing.