- Safer drug combination found for patients with high-risk atrial fibrillation
- How Amiodrone Works
- Serious Side Effects
- Major Drug Interactions
- Amiodarone Recall Information
- Hiring an Attorney to Prosecute Injuries Related to Amiodarone
- What is Amiodarone?
- What is amiodarone?
- Important Information
- Before taking this medicine
- How should I take amiodarone?
- Amiodarone dosing information
- What happens if I miss a dose?
- What happens if I overdose?
- What should I avoid while taking amiodarone?
- Amiodarone side effects
- What other drugs will affect amiodarone?
- Further information
- More about amiodarone
- Consumer resources
- Professional resources
- Related treatment guides
- Persistence Of Adverse Effects
- Pulmonary Toxicity
- Hepatic Injury
- Worsened Arrhythmia
- Visual Impairment And Loss of Vision
- Thyroid Abnormalities
- Implantable Cardiac Devices
- Fetal Toxicity
- Peripheral Neuropathy
- Photosensitivity And Skin Discoloration
- Patient Counseling Information
- Nonclinical Toxicology
- Carcinogenesis, Mutagenesis, Impairment Of Fertility
- Use In Specific Populations
- Labor And Delivery
- Females And Males Of Reproductive Potential
- Pediatric Use
- Geriatric Use
- amiodarone (Rx)
- Cordarone X 150 mg/3 ml Solution for Injection
See Article on Page 588-596
Amiodarone, first used in Europe for the treatment of angina pectoris in the 1960s, began to be widely utilized as an antiarrhythmic agent in the 1970s. Currently, it is one of the most commonly used antiarrhythmic agents for the treatment of almost all tachyarrhythmias; however, frequent occurrence of adverse effects is an important concern when deciding on its use.
In the current issue of The Korean Journal of Internal Medicine , type and frequency of adverse effects are reported among a relatively large number of amiodarone treated patients (n = 930) from a single institution. At mean follow-up of 2.7 years, 16.6% of patients experienced amiodarone related adverse effects and 15.1% had to discontinue the drug because of adverse effects.
The incidence of adverse effect was reported as high as 70% with 18% to 37% rate of adverse effect driven drug discontinuation at 5 years follow-up. The results of the article in this issue of the journal appear consistent with those in a practical guide published in 2007, with incidence of adverse effects of 15% during first year of amiodarone use increasing to up to 50% during long-term use ; there was higher frequency of adverse effects in patients on amiodarone for a long time which was amenable to reversal by dose lowering or drug discontinuation.
Rate of drug discontinuation secondary to drug adverse effects in the study in this issue; however, appears lower than the 22.9% rate reported in 1997 in a meta-analysis of low dose (daily average of 152 to 330 mg) amiodarone therapy for at least 1 year . As pointed out by the authors, the study in this issue was retrospective and mild adverse effects might have been missed or not recorded.
Pulmonary toxicity is one of the fatal adverse effects of amiodarone with mortality as high as 10% and incidence of approximately 2% in previous studies, even higher among older patients on higher doses . Pulmonary toxicity manifests with dyspnea, cough, fever, and pulmonary lesions usually progress if early detection is not made . For early detection of pulmonary toxicity, pulmonary function tests including diffusion capacity and chest X-ray are recommended every 3 months during the first year and twice yearly thereafter, or if not possible, at least chest X-ray once yearly. In principle, the drug should be discontinued if pulmonary toxicity is detected and corticosteroid used for significant toxicity.
Amiodarone is an iodinated derivate of benzofuran similar in structure to the thyroid hormones triiodothyronine (T3) and thyroxine (T4), and containing a large of amount of iodine; specifically, a 100 mg tablet contains 250 times the daily iodine requirement. Because of the latter features, use of amiodarone may cause thyroid damage and induce hypothyroidism with thyroid stimulating hormone (TSH) elevation in 2% to 4% of cases or hyperthyroidism with mainly increased T3 level in 1% to 2% of cases . Amiodarone treatment can initially elevate levels of TSH and free and total T4 while decreasing those of total and free T3. After achieving equilibrium at 3 months TSH is normalized while T4 and T3 remain at high and low normal levels, respectively. To detect such changes, thyroid function testing is recommended every 3 months during the first year and once or twice yearly thereafter . Amiodarone can cause bradycardia and conduction disturbance by depression of sinus or atrioventricular node and prolongation of myocardial refractoriness. In the article in this issue, frequency of these adverse effects was approximately 9.6% rendering them the most frequent, in contrast to the 3.3% to 5% reported in the meta-analysis of low dose amiodarone . These adverse effects can occur more frequently if patients are older or have structural heart disease.
Amiodarone through a direct drug effect causes prolongation of QT interval in almost all patients. Minimal QT prolongation after amiodarone treatment is not clinically significant, and in previous meta-analysis, low dose amiodarone use was associated with very small risk of severe QT prolongation and torsades de pointes .
The most common ocular change after long-term use of amiodarone is corneal epithelial opacities in 70% to 100% patients followed by lens opacities in 50% to 60% of patients. However, these changes do not affect eyesight and therefore drug discontinuation is not warranted. In rare cases of retinopathy or optic neuropathy, lowering dose or discontinuation of amiodarone should be considered . The study in this issue reports a very low frequency of 0.6% of ocular adverse events as compared to previous studies, again likely reflecting capture of serious adverse effects and not minor ones not affecting eyesight. A practical guide does not recommend regular eye examinations in patients without ocular symptoms .
Although it was not mentioned in the paper in this issue, amiodarone can cause other adverse effects including asymptomatic elevation of liver enzyme, neurologic dysfunction, photosensitivity, bluish skin discoloration, and gastroenterological disturbance. Further additional examinations are recommended if symptoms suggesting these adverse effects are shown in patients. Routine liver function test on a regular basis (every 6 weeks after amiodarone treatment) is recommended in the practical guide .
In Keimyung University Dongsan Medical Center, 876 patients who had taken amiodarone regularly over 3 months were retrospectively investigated . Overall incidence of adverse effects was 11.0% (69 patients) after an average of 24 months of amiodarone treatment. Hypothyroidism (60 patients, 6.9%) was the most common adverse effect followed by ocular (20 patients, 2.3%), pulmonary (10 patients, 1.1%), and skin adverse effect (six patients, 0.7%). Different incidence of adverse effects between the latter study and that in this issue is probably secondary to different treatment dose and duration.
Dronedarone is a new antiarrhythmic agent for the treatment of atrial fibrillation and flutter. Dronedarone exhibits similar pharmacological action to amiodarone but iodine was eliminated to reduce toxicity including pulmonary and thyroid toxicity. In the ATHENA study , use of dronedarone in paroxysmal or persistent atrial fibrillation patients with moderate risk of cardiovascular events significantly reduce cardiovascular events including unplanned cardiovascular hospitalization and all-cause mortality. The DIONYSOS study compared dronedarone (400 mg twice daily) and amiodarone (600 mg daily for 28 days, and 200 mg daily thereafter) over 6 months in terms of maintenance of sinus rhythm in atrial fibrillation patients. Recurrence rates of atrial fibrillation were 63% and 42% in the dronedarone and amiodarone groups, respectively, indicating less potency of dronedarone on sinus rhythm maintenance. However, through 7 months follow-up, dronedarone was associated with significantly less side effects and therefore with lower discontinuation rate. Thus, one could argue that dronedarone has a better safety profile even though it has decreased efficacy in preventing atrial fibrillation. However, dronedarone increases mortality in heart failure patients with NYHA class III/IV and permanent atrial fibrillation patients. Therefore, it is recommended that dronedarone be avoided in patients with heart failure or permanent atrial fibrillation.
Taken altogether, there seems to be small risk of either minor/fatal adverse effects or death with low doses of amiodarone (less than 200 mg per day). However, it is important to keep in mind that long-term treatment of amiodarone is associated with occurrence of adverse effects warranting regular follow-up examinations for their early detection.
- Sogol PB, Hershman JM, Reed AW, Dillmann WH. The effects of amiodarone on serum thyroid hormones and hepatic thyroxine 5′-monodeiodination in rats. Endocrinology. 1983 Oct;113(4):1464–1469.
- Bürgi H, Wimpfheimer C, Burger A, Zaunbauer W, Rösler H, Lemarchand-Béraud T. Changes of circulating thyroxine, triiodothyronine and reverse triiodothyronine after radiographic contrast agents. J Clin Endocrinol Metab. 1976 Dec;43(6):1203–1210.
- Burger A, Dinichert D, Nicod P, Jenny M, Lemarchand-Béraud T, Vallotton MB. Effect of amiodarone on serum triiodothyronine, reverse triiodothyronine, thyroxin, and thyrotropin. A drug influencing peripheral metabolism of thyroid hormones. J Clin Invest. 1976 Aug;58(2):255–259.
- Charlier R, Baudine A, Chaillet F. Recherches dan la série des benzofurannes. XXXII. Mode d’action de l’amiodarone sur le système cardiovasculaire. Arch Int Physiol Biochim. 1967 Dec;75(5):787–808.
- Freedberg AS, Papp JG, Williams EM. The effect of altered thyroid state on atrial intracellular potentials. J Physiol. 1970 Apr;207(2):357–369.
- Gloor HO, Urthaler F, James TN. Acute effects of amiodarone upon the canine sinus node and atrioventricular junctional region. J Clin Invest. 1983 May;71(5):1457–1466.
- Heger JJ, Prystowsky EN, Jackman WM, Naccarelli GV, Warfel KA, Rinkenberger RL, Zipes DP. Clinical efficacy and electrophysiology during long-term therapy for recurrent ventricular tachycardia or ventricular fibrillation. N Engl J Med. 1981 Sep 3;305(10):539–545.
- Lauber K. Iodine determination in biological material. Kinetic measurement of the catalytic activity of iodide. Anal Chem. 1975 Apr;47(4):769–771.
- Leutenegger A, Lüthy E. Eine neue Substanz in der Therapie der Angina pectoris: Amiodarone. Schweiz Med Wochenschr. 1968 Dec 21;98(51):2020–2025.
- Melmed S, Nademanee K, Reed AW, Hendrickson JA, Singh BN, Hershman JM. Hyperthyroxinemia with bradycardia and normal thyrotropin secretion after chronic amiodarone administration. J Clin Endocrinol Metab. 1981 Nov;53(5):997–1001.
- Nademanee K, Singh BN, Hendrickson JA, Reed AW, Melmed S, Hershman J. Pharmacokinetic significance of serum reverse T3 levels during amiodarone treatment: a potential method for monitoring chronic drug therapy. Circulation. 1982 Jul;66(1):202–211.
- Polster P, Broekhuysen J. The adrenergic antagonism of amiodarone. Biochem Pharmacol. 1976 Jan 15;25(2):131–134.
- Richtarik A, Woolsey TA, Valdivia E. Method for recording ECG’s in unanesthetized guinea pigs. J Appl Physiol. 1965 Sep;20(5):1091–1093.
- Rosenbaum MB, Chiale PA, Halpern MS, Nau GJ, Przybylski J, Levi RJ, Lázzari JO, Elizari MV. Clinical efficacy of amiodarone as an antiarrhythmic agent. Am J Cardiol. 1976 Dec;38(7):934–944.
- Silva JE, Larsen PR. Pituitary nuclear 3,5,3′-triiodothyronine and thyrotropin secretion: an explanation for the effect of thyroxine. Science. 1977 Nov 11;198(4317):617–620.
- Singh BN, Vaughan Williams EM. The effect of amiodarone, a new anti-anginal drug, on cardiac muscle. Br J Pharmacol. 1970 Aug;39(4):657–667.
- Stäubli M, Bircher J, Galeazzi RL, Remund H, Studer H. Serum concentrations of amiodarone during long term therapy. Relation to dose, efficacy and toxicity. Eur J Clin Pharmacol. 1983;24(4):485–494.
- Studer H, Forster R, Conti A, Kohler H, Haeberli A, Engler H. Transformation of normal follicles into thyrotropin-refractory “cold” follicles in the aging mouse thyroid gland. Endocrinology. 1978 May;102(5):1576–1586.
- Van Schepdael J, Solvay H. Etude clinique de l’amiodarone dans les troubles du rythme cardiaque. Presse Med. 1970 Oct 10;78(42):1849–1850.
The following serious adverse reactions are described in more detail in other sections of the prescribing information:
- Pulmonary Toxicity
- Hepatic Injury
- Worsened Arrhythmia
- Visual Impairment and Loss of Vision
- Thyroid Abnormalities
- Peripheral Neuropathy
- Photosensitivity and Skin Discoloration
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.
At the usual maintenance dose (400 mg/day) and above, CORDARONE causes adverse reactions in about three-fourths of all patients, resulting in discontinuation in 7 to 18%.
In surveys of almost 5,000 patients treated in open U.S. studies and in published reports of treatment with CORDARONE, the adverse reactions most frequently requiring discontinuation of CORDARONE 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, photosensitivity, blue skin discoloration, hyperthyroidism, and hypothyroidism.
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):
Common: Hypothyroidism, hyperthyroidism.
Common: Congestive heart failure, cardiac arrhythmias, SA node dysfunction.
Very common: Nausea, vomiting.
Common: Constipation, anorexia, abdominal pain.
Common: Solar dermatitis/photosensitivity.
Common: Malaise and fatigue, tremor/abnormal involuntary movements, lack of coordination, abnormal gait/ataxia, dizziness, paresthesias, decreased libido, insomnia, headache, sleep disturbances.
Common: Visual disturbances.
Common: Abnormal liver-function tests, nonspecific hepatic disorders.
Common: Pulmonary inflammation or fibrosis.
Common: Flushing, abnormal taste and smell, edema, abnormal salivation, coagulation abnormalities.
Uncommon: Blue skin discoloration, rash, spontaneous ecchymosis, alopecia, hypotension, and cardiac conduction abnormalities.
The following adverse reactions have been identified during post-approval use of CORDARONE. 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.
Hematologic: hemolytic anemia, aplastic anemia, pancytopenia, neutropenia, thrombocytopenia, agranulocytosis, granuloma.
Immune: anaphylactic/anaphylactoid reaction (including shock), angioedema.
Neurologic: pseudotumor cerebri, parkinsonian symptoms such as akinesia and bradykinesia (sometimes reversible with discontinuation of therapy), demyelinating polyneuropathy.
Psychiatric: hallucination, confusional state, disorientation, delirium.
Cardiac: hypotension (sometimes fatal), sinus arrest.
Respiratory: eosinophilic pneumonia, acute respiratory distress syndrome in the post-operative setting, bronchospasm, bronchiolitis obliterans organizing pneumonia, pulmonary alveolar hemorrhage, pleural effusion, pleuritis.
Gastrointestinal: pancreatitis, acute pancreatitis.
Hepatic: hepatitis, cholestatic hepatitis, cirrhosis.
Skin and Subcutaneous Tissue Disorders: urticaria, toxic epidermal necrolysis (sometimes fatal), erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, bullous dermatitis, drug rash with eosinophilia and systemic symptoms (DRESS), eczema, pruritus, skin cancer, lupus-like syndrome.
Musculoskeletal: myopathy, muscle weakness, rhabdomyolysis.
Renal: renal impairment, renal insufficiency, acute renal failure.
Reproductive: epididymitis, impotence.
Body as a whole: fever, dry mouth.
Endocrine and metabolic: thyroid nodules/ thyroid cancer, syndrome of inappropriate antidiuretic hormone secretion (SIADH).
Read the entire FDA prescribing information for Cordarone (Amiodarone HCl Tablets)
If you have atrial fibrillation (AF), a type of irregular heartbeat, you may be prescribed amiodarone (Cordarone, Pacerone). It’s commonly used to decrease the frequency of AF episodes when using a rhythm control strategy (trying to regulate the rhythm of your heartbeat).
Some people with AF will instead be prescribed medications to slow and control the heart rate, for example, a beta blocker like metoprolol. Others, however, will need an anti-arrhythmia medication like amiodarone—a medication that keeps your heart in normal rhythm.
Amiodarone is the main rhythm medication used—so is it safe? Here are 7 things to know.
- Do I need it? Beta blockers like metoprolol may be effective in maintaining normal rhythm and can be tried first in some patients. Your cardiologist will help you decide what’s best for you, but for if you have structural heart disease (valve problems, for example) amiodarone is often suggested.
- Does amiodarone work to keep me in normal rhythm and out of AF? Yes, amiodarone is effective for the maintenance of sinus rhythm and is consistently more effective than the other antiarrhythmic drugs.
- Can I take amiodarone if I have heart failure too? Yes, for atrial fibrillation patients with heart failure or left ventricular hypertrophy, amiodarone is preferred over other options like flecainide or propafenone (other antiarrhythmic medications).
- What about amiodarone and the lungs? The most important downside and potential toxicity of amiodarone is lung toxicity. Lung inflammation (hypersensitivity pneumonitis or interstitial/alveolar pneumonitis) can occur up to 10% of the time.
- What other side effects does amiodarone have? Dizziness and ataxia (feeling off-balance and walking wobbly), nausea and loss of appetite are also known side effects and occur about 10 – 30% of the time.
- What about amiodarone and the thyroid? This is complicated, as amiodarone may cause over- or underactive thyroid and should be used with caution if you have thyroid disease. Your thyroid function should be monitored prior to treatment and periodically thereafter. Why does this happen? Amiodarone has a direct effect on the thyroid, and has iodine in it, which may also lead to problems with the thyroid.
- Is the newer anti-arrhythmic Multaq better than amiodarone? Multaq (dronedarone) is an expensive brand-name-only medication similar to amiodarone. Multaq is better tolerated and has fewer side effects than amiodarone—but it doesn’t work as well. Patients taking Multaq for prevention of atrial fibrillation are half as likely to remain in sinus rhythm as patients on amiodarone.
Safer drug combination found for patients with high-risk atrial fibrillation
Although the anticoagulant warfarin has been the standard of care since the 1940s, more recent advancements in blood-thinning medication led to the development of the drug apixaban. The 2011 ARISTOTLE trial, conducted internationally, found that patients with atrial fibrillation taking apixaban had fewer strokes than those taking warfarin.
Greg Flaker, M.D., the Wes and Simone Sorenson Chair in Cardiovascular Research at the MU School of Medicine, directed a team of researchers who recently reviewed data from the ARISTOTLE trial.
Flaker’s study indicated that the rate of stroke or blood clot to the body was 39 percent lower in those patients taking the amiodrarone-apixiban drug combination, compared to taking the amiodarone-warfarin combination.
“Although warfarin works very well for most patients who take it, we know that it can be a difficult medication to regulate ? especially when combining it with another drug,” Flaker said. “About 30 percent of patients taking warfarin experience fluctuations in blood thickness, depending on how warfarin is metabolized by the individual. Interaction with another drug, such as amiodarone, also affects how warfarin is metabolized.”
“Amiodarone is a common and effective drug used to normalize irregular heart rhythm caused by atrial fibrillation,” Flaker said. “However, because clotting is a complication associated with the condition, an anticoagulant or blood thinner is frequently used to reduce that possibility. Warfarin has been used as a blood thinner in this capacity for quite some time.”
Flaker, a member of the Steering Committee for the earlier ARISTOTLE clinical trial, and his research team reviewed data from that trial in their study.
“Our study mirrored the ARISTOTLE trial in that apixaban proved to be a better blood -thinning medication for all patients with atrial fibrillation,” Flaker said. “We looked at the specific drug combination of apixaban and amiodarone. We found that if you had atrial fibrillation and were taking amiodarone to control your heart rhythm, your stroke risk would be higher if you took warfarin than if you took apixaban.”
“Certainly there are factors such as cost, physician preference and patient decision-making that affect what drug we use to reduce stroke risks,” Flaker said. “The good news for AFib patients is that there is a very good alternative to warfarin for their physicians to consider when developing care strategies for patients with high-risk atrial fibrillation.”
The study led by Flaker recently was published in the Journal of the American College of Cardiology, a publication of the American College of Cardiology Foundation.
Amiodarone may cause lung damage that can be serious or life-threatening. Tell your doctor if you have or have ever had any type of lung disease or if you have ever developed lung damage or breathing problems while taking amiodarone. If you experience any of the following symptoms, call your doctor immediately: fever, shortness of breath, wheezing, other breathing problems, cough, or coughing or spitting up blood.
Amiodarone may also cause liver damage. Tell your doctor if you have or have ever had liver disease. If you experience any of the following symptoms, call your doctor immediately: nausea, vomiting, dark colored urine, excessive tiredness, yellowing of the skin or eyes, itching, or pain in the upper right part of the stomach.
Amiodarone may cause your arrhythmia (irregular heart rhythm) to worsen or may cause you to develop new arrhythmias. Tell your doctor if you have ever been dizzy or lightheaded or have fainted because your heartbeat was too slow and if you have or have ever had low levels of potassium or magnesium in your blood; heart or thyroid disease; or any problems with your heart rhythm other than the arrhythmia that is being treated. Tell your doctor and pharmacist if you are taking any of the following medications: antifungals such as fluconazole (Diflucan), ketoconazole (Nizoral), and itraconazole (Onmel, Sporanox); azithromycin (Zithromax, Zmax); beta blockers such as propranolol (Hemangeol, Inderal, Innopran); calcium channel blockers such as diltiazem (Cardizem, Cartia, Diltzac, Tiazac, others), and verapamil (Calan, Covera, Verelan, in Tarka); cisapride (Propulsid; not available in the US); clarithromycin (Biaxin); clonidine (Catapres, Kapvay); diuretics (‘water pills’); dofetilide (Tikosyn); erythromycin (E.E.S., E-Mycin, Erythrocin); fluoroquinolone antibiotics such as ciprofloxacin (Cipro), levofloxacin (Levaquin), lomefloxacin (not available in the US), moxifloxacin (Avelox), norfloxacin (not available in the US), ofloxacin, and sparfloxacin (not available in the US); other medications for irregular heartbeat such as digoxin (Lanoxin), disopyramide (Norpace), flecainide, ivabradine (Corlanor), phenytoin (Dilantin, Phenytek), procainamide, quinidine (in Nuedexta), and sotalol (Betapace, Sorine, Sotylize); and thioridazine. If you have any of the following symptoms, call your doctor immediately: lightheadedness; fainting; fast, slow, or pounding heartbeat; or feeling that your heart has skipped a beat.
You will probably be hospitalized for one week or longer when you begin your treatment with amiodarone. Your doctor will monitor you carefully during this time and for as long as you continue to take amiodarone. Your doctor will probably start you on a high dose of amiodarone and gradually decrease your dose as the medication begins to work. Your doctor may decrease your dose during your treatment if you develop side effects. Follow your doctor’s directions carefully.
Do not stop taking amiodarone without talking to your doctor. You may need to be closely monitored or even hospitalized when you stop taking amiodarone. Amiodarone may remain in your body for some time after you stop taking it, so your doctor will watch you carefully during this time.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests, such as blood tests, X-rays, and electrocardiograms (EKGs, tests that record the electrical activity of the heart) before and during your treatment to be sure that it is safe for you to take amiodarone and to check your body’s response to the medication.
Your doctor or pharmacist will give you the manufacturer’s patient information sheet (Medication Guide) when you begin treatment with amiodarone and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also obtain the Medication Guide from the FDA website: http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm.
Talk to your doctor about the risks of taking amiodarone.
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Amiodarone (pacerone & nexterone) is a medication formulated to improve heartbeat rhythm. Doctors prescribe the drug to patients with life-threatening ventricle-related heart rhythm disorders to ensure the heart beats normally. The ventricles are the heart’s lower chambers that allow blood flow out from the heart.
The medication Amiodarone (pacerone) is affected for treating ventricular fibrillation and ventricular tachycardia. The medication was first discovered in 1961 and received final FDA approval in December 1985. The drug has not been approved by the Food and Drug Administration (FDA) for any other condition.
How Amiodrone Works
When the broad-spectrum antiarrhythmic drug is either taken orally or through an injection, Amiodarone (pacerone) can correct abnormal heart rate rhythms. However, the medication can lead to serious side effects that could be severe or fatal. The drug is known to produce complex effects on the heart’s electrical activity that is responsible for maintaining rhythm. The drug works by:
- Delaying heart rate by recharging the electrical system once the heart has contracted after a beat;
- Prolong the heart’s electrical phase when the muscle cells of the heart are stimulated through in electrical response;
- Slow the speed of the heart’s electrical conduction;
- Reduce the rapidity of the heart’s electrical impulse firing as a natural heart pacemaker;
- Slow electrical conduction through numerous illogical pathways responsible for causing an arrhythmia.
The medication might also affect the heart because it dilates (enlarges) blood vessels that can help drop blood pressure that might be especially important for patients suffering congenital heart failure.
Serious Side Effects
The FDA has initiated Black Box (most serious) Warnings to alert patients and their doctors about the dangerous side effects associated with Amiodarone (pacerone & nexterone). The FDA states that the medication should be used only if the patient has a life-threatening irregular heartbeat or arrhythmia. This is because the drug poses serious side effects that could involve severe liver problems, lung issues, loss of vision, and a worsening of the patient’s already irregular heartbeat.
The FDA warns that all patient should take the first dose of brand-name Amiodarone or generic form pacerone after being admitted to the hospital to ensure the safety of their well-being and the drug’s efficacy. The nursing staff and doctor will likely need to monitor the patient while in the hospital to ensure they receive the correct dosage. Known specific side effects include:
- Elevated Risk of Developing Vision Problems – Amiodarone (pacerone & nexterone) can cause the patient’s eyes to become dry, requiring OTC artificial tears or lubricating eye solutions. Patients who develop blurry vision problems often see halos that appear around objects or develop a high sensitivity to light.
- Sun Sensitivity – This medication can increase a patient’s sensitivity to the sun or turn their skin to a gray/bluish color. It is recommended that patients taking Amiodarone (pacerone & nexterone) avoid sun rays and wear protective clothing/sunscreen when out in the sun for minutes or hours. Doctors recommend that patients should avoid using tanning beds or sun lamps to prevent severe sunburns.
- Elevated Risk of Developing Lung Problems – Some patients taking Amiodarone (pacerone & nexterone) have developed fatal lung injuries and lung disease. Common Amiodrone-related lung problem symptoms involve shortness of breath, difficulty in breathing, wheezing, spitting up blood, and/or chest pain.
- Allergic Reactions including height, itching, skin rash, and swelling of the tongue, based and/or lips.
- Liver Problems – Some individuals develop unusual symptoms involving the liver including dark urine, unusual weakness, and tiredness or a yellowing of the skin (jaundice) of the whites of the eyes.
- Gut Issues – Nausea, vomiting, spitting up blood and severe stomach pains can be common stomach problem symptoms associated with taking the brand-name a generic version of the heart rhythm medication.
- Thyroid Problems – Thinning hair, weight gain, weight loss, weakness, decreased tolerance for cold or heat or increased skin sensitivity could all be signs of thyroid problems associated with taking this medication.
- Nerve Damage – Difficulty in walking, uncontrolled movements, muscle weakness or neuropathy (numbness, tingling, or pain) in the feet and/or hands might be a sign of Amiodarone-related side effects.
More common but less serious symptoms and side effects associated with taking Amiodarone (pacerone & nexterone) include:
- Nausea and vomiting
- Lack of coordination
- Stomach pain
- Unusual or uncontrollable body movements
- Diminished sexual drive and/or performance
Major Drug Interactions
Amiodarone (pacerone) as an oral tablet form has serious interactions with some other drugs, vitamins, supplements, and herbs when taken. Because of that, patients should discuss the management of their medications with their doctors. Even a mild drug interaction can cause serious problems in patients with an already irregular heart rate. The most common medication interactions involving Amiodarone (pacerone & nexterone) include:
- Antibiotic Medications – Taking Amiodarone (pacerone) concomitantly with some antibiotics could exacerbate an irregular heartbeat. These antibiotics include levofloxacin, fluconazole, clarithromycin, and erythromycin.
- Antiviral Medications – Taking Amiodarone (pacerone & nexterone) together with antiviral medications could exacerbate already serious side effects like an irregular heartbeat that could lead to a fatal outcome. Because of that, the doctor must closely monitor their patient when taking antiviral drugs with Amiodarone or generic version. These drugs include:
- Blood Thinners – Taking warfarin or other blood thinners concomitantly with Amiodarone (pacerone) could increase the potential risk of the patient experiencing serious bleeding that could lead to death. Because of that, the doctor must monitor the patient’s condition and adjust their dose of blood thinners to minimize any potential risk of harm or death.
- OTC Cough Medicines – Using Amiodarone (pacerone) with dextromethorphan could lead to toxic levels of accumulated dextromethorphan.
- Depression Medication – Some antidepressant medications including trazodone could cause an accumulation of Amiodarone amounts causing serious and sometimes fatal side effects including an irregular heartbeat.
- Organ Transplant Medications – Some patients take medications to prevent the rejection of an organ transplant, including cyclosporine when used concomitantly with Amiodarone could result in accumulated amounts of cyclosporine and cause serious side effects.
- GERD Medications – Taking certain GERD medications including cimetidine together with Amiodarone has the potential of increasing the heart rhythm medication levels in the body which could lead to serious or fatal side effects including an irregular heartbeat.
- Heart Failure Drugs – Taking Amiodarone concomitantly with ivabradine can slow the body’s heart rate down and lead to serious a heart rhythm disorder.
- Heart Treatment Drugs – When prescribing Amiodarone or the generic versions, the treating doctor needs to be aware if their patient is taking other heart treatment drug including flecainide, procainamide, quinidine or other antiarrhythmic medications or digoxin that could reduce the dosage effects of Amiodarone.
- Hepatitis Medications – Some hepatitis drugs when used concomitantly with the heart rhythm medication have the potential of causing severe or life-threatening bradycardia by slowing patient’s heart rate. These drugs include sofosbuvir/simeprevir and Ledipasvir/sofosbuvir.
- Supplements and Herbs – Taking Amiodarone together with St. John’s Wort is known to lower the heartbeat regulating drug levels in the body, reducing the efficiency of the heart rhythm controlling medication.
- High Blood Pressure Drugs – Doctors should be cautious when prescribing Amiodarone with high blood pressure drugs because it could produce serious side effects. These drugs include all beta-blockers and calcium channel blockers.
- High Cholesterol Medication – Taking atorvastatin or simvastatin with Amiodarone could increase cholesterol medication levels in the bloodstream leading to serious and life-threatening side effects. The statin cholestyramine, when taken with the heart rhythm medication, can lower Amiodrone levels in the body, and reduce its efficacy.
- Local Anesthesia Medications – including lidocaine taken concomitantly with Amiodarone can produce debilitating seizures can slow the patient’s heart rate.
- Fentanyl Pain Drugs – taken together with Amiodarone can lower blood pressure, decreased heart rate, and diminish blood flow levels in the heart.
- Seizure Medications – including phenytoin, when taken concomitantly with Amiodarone, has the potential of diminishing Amiodrone levels in the body and diminish its efficacy.
Amiodarone Recall Information
In May 2011, the FDA initiated a Drug Safety Communication concerning connection problems with “certain needle’s pre-filled glass syringes containing adenosine and Amiodarone.” The safety communication alerted the healthcare community after receiving reports “that the adenosine and Amiodarone pre-filled glass syringes can become clogged and malfunction during the process of connecting them to the pin-activated needless IV Access system.”
The Safety Communication Report noted that the “incompatibility is not detected until after the syringe is inserted into the pin-activated needless IV access system. The action of inserting the syringe can cause the pin in the access system to clog or break off in the syringe tip, preventing delivery of the medication.”
The FDA Safety Warning also noted that in some cases “the syringe may damage the IV tubing and/or the needless access system and require reestablishment of the IV access. These can cause a delay in administration of the medication in emergency situations, and could potentially result in serious harm to patients.”
The brand-name Amiodarone and its generic forms pacerone and nexterone can produce severe side effects that require emergency medical attention. Individuals who have allergic reactions should seek out immediate medical assistance if they develop hives, swelling of the face, tongue, lips, or throat, or have difficulty in breathing. The FDA says that patients should avoid using the drug if allergic to iodine or have specific heart conditions including an AV block or a personal medical history of slower heart beats.
Hiring an Attorney to Prosecute Injuries Related to Amiodarone
If you have suffered serious injuries after taking Amiodarone or the generic versions pacerone and nexterone, you are likely entitled to receive financial compensation for your damages. Our Amiodarone attorneys at the Drug Law Center working on your behalf can file a compensation claim or lawsuit against the medication manufacturer. We work on “no upfront payment” contingency arrangement, meaning if we are unable to secure a financial settlement through negotiation or win your case at trial, you owe us nothing.
What is Amiodarone?
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Abiraterone Acetate
- Agalsidase Alfa
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Chloral Hydrate
- Dabigatran Etexilate
- Doxorubicin Hydrochloride Liposome
- Ginkgo Biloba
- Inotuzumab Ozogamicin
- Morphine Sulfate Liposome
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- St John’s Wort
- Vincristine Sulfate Liposome
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Generic Name: amiodarone tablets (oral) (A mi OH da rone)
Brand Names: Pacerone
Medically reviewed by P. Thornton, DipPharm Last updated on May 28, 2019.
- Side Effects
What is amiodarone?
Amiodarone affects the rhythm of your heartbeats. It is used to help keep the heart beating normally in people with life-threatening heart rhythm disorders of the ventricles (the lower chambers of the heart that allow blood to flow out of the heart).
Amiodarone is used to treat ventricular tachycardia or ventricular fibrillation.
Amiodarone is for use only in treating life-threatening heart rhythm disorders.
Amiodarone can cause dangerous side effects on your heart, liver, lungs, or vision.
You should not take this medicine if you are allergic to amiodarone or iodine, or if you have heart block, a history of slow heartbeats that have caused you to faint, or if your heart cannot pump blood properly.
Call your doctor or get medical help at once if you have: chest pain, fast or pounding heartbeats, trouble breathing, vision problems, upper stomach pain, vomiting, dark urine, jaundice (yellowing of the skin or eyes), or if you cough up blood.
Tell your doctor if you have signs of a thyroid problem, such as weight changes, extreme tiredness, dry skin, thinning hair, feeling too hot or too cold, irregular menstrual periods, or swelling in your neck (goiter).
Before taking this medicine
You should not use amiodarone if you have:
a serious heart condition called “AV block” (2nd or 3rd degree), unless you have a pacemaker;
a history of slow heartbeats that have caused you to faint; or
if your heart cannot pump blood properly.
Amiodarone can cause dangerous side effects on your heart, liver, lungs, or thyroid.
To make sure this medicine is safe for you, tell your doctor if you have ever had:
asthma or another lung disorder;
a thyroid disorder;
high or low blood pressure;
an electrolyte imbalance (such as low levels of potassium or magnesium in your blood); or
if you have a pacemaker or defibrillator implanted in your chest.
Taking amiodarone during pregnancy may harm an unborn baby, or cause thyroid problems or abnormal heartbeats in the baby after it is born. Amiodarone may also affect the child’s growth or development (speech, movement, academic skills) later in life. Tell your doctor if you are pregnant or if you become pregnant.
You should not breast-feed while taking this medicine, and for several months after stopping. Amiodarone takes a long time to clear from your body. Talk to your doctor about the best way to feed your baby during this time.
How should I take amiodarone?
Take amiodarone exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.
You will receive your first few doses in a hospital setting, where your heart rhythm can be monitored.
If you have been taking another heart rhythm medicine, you may need to gradually stop taking it when you start using amiodarone. Follow your doctor’s dosing instructions very carefully.
You may take the tablets with or without food, but take it the same way each time.
It may take up to 3 weeks before your heart rhythm improves. Keep using the medicine as directed even if you feel well.
Amiodarone can have long lasting effects on your body. You may need frequent medical tests while using this medicine and for several months after your last dose.
If you need surgery (including laser eye surgery), tell the surgeon ahead of time that you are using amiodarone.
This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using this medicine.
Store at room temperature away from moisture, heat, and light.
Amiodarone dosing information
Usual Adult Dose for Arrhythmias:
Initial dose: 1000 mg over the first 24 hours of therapy, delivered by the following infusion regimen:
-Loading infusions: 150 mg over the first 10 minutes (15 mg/min), followed by 360 mg over the next 6 hours (1 mg/min)
-Maintenance infusion: 540 mg over the remaining 18 hours (0.5 mg/min)
Maintenance dose: After the first 24 hours, continue the maintenance infusion rate of 0.5 mg/min; may increase infusion rate to achieve effective arrhythmia suppression.
-Supplemental infusions: 150 mg over 10 minutes (15 mg/min) for breakthrough episodes of ventricular fibrillation (VF) or hemodynamically unstable ventricular tachycardia (VT)
Maximum dose: Initial infusion rate: 30 mg/min
Duration of therapy: Until ventricular arrhythmias stabilize (most patients require 48 to 96 hours); maintenance infusion of up to 0.5 mg/min can be continued for up to 3 weeks.
Comments: Mean daily doses greater than 2100 mg for the first 24 hours were associated with increased risk of hypotension.
Use: Initiation of treatment and prophylaxis of frequently recurring VF and hemodynamically unstable VT in patients refractory to other therapy.
Loading dose: 800 to 1600 mg orally per day for 1 to 3 weeks (occasionally longer) until adequate arrhythmia control is achieved or if side effects become prominent, then switch to adjustment dose
Adjustment dose: 600 to 800 mg orally per day for 1 month, then switch to maintenance dose
Maintenance dose: 400 mg orally per day
-May be administered once a day; twice a day dosing is recommended for total daily doses of 1000 mg or more or in patients who experience gastrointestinal tolerance.
-Close monitoring is indicated during the loading phase and surrounding any dose adjustments.
-Maintenance dose should be determined according to antiarrhythmic effect as assessed by patient tolerance as well as symptoms, Holter recordings, and/or programmed electrical stimulation; some patients may require up to 600 mg/day while some can be controlled on lower doses.
Use: Treatment of life-threatening recurrent VF or life-threatening recurrent hemodynamically unstable VT in patients refractory to adequate doses of other antiarrhythmics or those intolerant of alternative agents.
What happens if I miss a dose?
Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of amiodarone can be fatal.
Overdose symptoms may include weakness, slow heart rate, feeling light-headed, or loss of consciousness.
What should I avoid while taking amiodarone?
Avoid driving or hazardous activity until you know how amiodarone will affect you. Your reactions could be impaired.
Grapefruit may interact with amiodarone and lead to unwanted side effects. Avoid the use of grapefruit products.
Avoid taking an herbal supplement containing St. John’s wort.
Amiodarone could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.
Amiodarone side effects
Get emergency medical help if you have signs of an allergic reaction to amiodarone: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Amiodarone takes a long time to completely clear from your body. You may continue to have side effects from this medicine after you stop using it.
Call your doctor at once if you have any of these side effects, even if they occur up to several months after you stop using this medicine:
wheezing, cough, chest pain, cough with bloody mucus, fever;
a new or a worsening irregular heartbeat pattern (fast, slow, or pounding heartbeats);
a light-headed feeling, like you might pass out;
blurred vision, seeing halos around lights (your eyes may be more sensitive to light);
liver problems – nausea, vomiting, stomach pain (upper right side), tiredness, dark urine, jaundice (yellowing of the skin or eyes);
nerve problems – loss of coordination, muscle weakness, uncontrolled muscle movement, or a prickly feeling in your hands or lower legs;
signs of overactive thyroid – weight loss, thinning hair, feeling hot, increased sweating, tremors, feeling nervous or irritable, irregular menstrual periods, swelling in your neck (goiter); or
signs of underactive thyroid – weight gain, tiredness, depression, trouble concentrating, feeling cold.
Common amiodarone side effects may include:
nausea, vomiting, loss of appetite; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect amiodarone?
Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.
Amiodarone takes a long time to completely clear from your body. Drug interactions are possible for up to several months after you stop using amiodarone. Talk to your doctor before taking any medication during this time. Keep track of how long it has been since your last dose of amiodarone.
Many drugs can interact with amiodarone. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use amiodarone only for the indication prescribed.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Copyright 1996-2020 Cerner Multum, Inc. Version: 7.01.
More about amiodarone
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
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- Support Group
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- 68 Reviews
- Drug class: group III antiarrhythmics
- FDA Alerts (3)
- Amiodarone Tablets
- Amiodarone Injection Solution
- Amiodarone Intravenous (Advanced Reading)
- Amiodarone Intravenous, Oral (Advanced Reading)
Other brands: Pacerone, Cordarone, Nexterone, Cordarone IV
- Amiodarone Hydrochloride (AHFS Monograph)
- … +3 more
Related treatment guides
- Ventricular Fibrillation
- Supraventricular Tachycardia
- Ventricular Tachycardia
Included as part of the PRECAUTIONS section.
Persistence Of Adverse Effects
Because of the long half-life of amiodarone (15 to 142 days) and its active metabolite desethylamiodarone (14 to 75 days), adverse reactions and drug interactions can persist for several weeks following amiodarone discontinuation .
CORDARONE may cause a clinical syndrome of cough and progressive dyspnea accompanied by functional, radiographic, gallium-scan, and pathological data consistent with pulmonary toxicity. Pulmonary toxicity secondary to CORDARONE may result from either indirect or direct toxicity as represented by hypersensitivity pneumonitis (including eosinophilic pneumonia) or interstitial/alveolar pneumonitis, respectively. Rates of pulmonary toxicity have been reported to be as high as 17% and is fatal in about 10% of cases. Obtain a baseline chest X-ray and pulmonary-function tests, including diffusion capacity, when CORDARONE therapy is initiated. Repeat history, physical exam, and chest X-ray every 3 to 6 months or if symptoms occur. Consider alternative antiarrhythmic therapy if the patient experiences signs or symptoms of pulmonary toxicity. Prednisone 40 to 60 mg/day tapered over several weeks may be helpful in treating pulmonary toxicity.
Adult Respiratory Distress Syndrome (ARDS)
Postoperatively, occurrences of ARDS have been reported in patients receiving CORDARONE therapy who have undergone either cardiac or noncardiac surgery. Although patients usually respond well to vigorous respiratory therapy, in rare instances the outcome has been fatal.
Asymptomatic elevations of hepatic enzyme levels are seen frequently, but CORDARONE can cause life-threatening hepatic injury. Histology has resembled that of alcoholic hepatitis or cirrhosis. Obtain baseline and periodic liver transaminases. If transaminases exceed three times normal, or doubles in a patient with an elevated baseline, discontinue or reduce dose of CORDARONE, obtain follow-up tests and treat appropriately.
CORDARONE can exacerbate the presenting arrhythmia in about 2 to 5% of patients or cause new ventricular fibrillation, incessant ventricular tachycardia, increased resistance to cardioversion, and polymorphic ventricular tachycardia associated with QTc prolongation (Torsade de Pointes ).
Correct hypokalemia, hypomagnesemia, and hypocalcemia before initiating treatment with CORDARONE, 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 receiving drugs affecting electrolyte levels, such as diuretics, laxatives, systemic corticosteroids, or amphotericin B.
Visual Impairment And Loss of Vision
Optic Neuropathy And Optic Neuritis
Cases of optic neuropathy and optic neuritis, usually resulting in visual impairment and sometimes permanent blindness, have been reported in patients treated with amiodarone and may occur at any time during therapy. If symptoms of visual impairment appear, such as changes in visual acuity and decreases in peripheral vision, consider discontinuing CORDARONE and promptly refer for ophthalmic examination. Regular ophthalmic examination, including funduscopy and slit-lamp examination, is recommended during administration of CORDARONE .
Corneal microdeposits appear in the majority of adults treated with CORDARONE. They are usually discernible only by slit-lamp examination, but give rise to symptoms such as visual halos or blurred vision in as many as 10% of patients. Corneal microdeposits are reversible upon reduction of dose or termination of treatment. Asymptomatic microdeposits alone are not a reason to reduce dose or discontinue treatment .
CORDARONE inhibits peripheral conversion of thyroxine (T4) to triiodothyronine (T3) and may cause increased thyroxine levels, decreased T3 levels, and increased levels of inactive reverse T3 (rT3) in clinically euthyroid patients. CORDARONE can cause either hypothyroidism (reported in up to 10% of patients) or hyperthyroidism (occurring in about 2% of 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. CORDARONE-induced hyperthyroidism may be followed by a transient period of hypothyroidism.
Hypothyrodism may be primary or subsequent to resolution of preceding amiodarone-induced hyperthyroidism. Severe hypothyroidism and myxedema coma, sometimes fatal, have been reported in association with amiodarone therapy. In some clinically hypothyroid amiodarone-treated patients, free thyroxine index values may be normal. Manage hypothyroidism by reducing the dose of or discontinuing CORDARONE and thyroid hormone supplementation.
CORDARONE causes symptomatic bradycardia or sinus arrest with suppression of escape foci in 2 to 4% of patients. The risk is increased by electrolytic disorders or use of concomitant antiarrhythmics or negative chronotropes . Bradycardia may require a pacemaker for rate control.
Postmarketing cases of symptomatic bradycardia, some requiring pacemaker insertion and at least one fatal, have been reported when ledipasvir/sofosbuvir or sofosbuvir with simeprevir were initiated in patients on amiodarone. Bradycardia generally occurred within hours to days, but in some cases presented up to 2 weeks after initiating antiviral treatment. Bradycardia generally resolved after discontinuation of antiviral treatment. The mechanism for this effect is unknown. Monitor heart rate in patients taking or recently discontinuing amiodarone when starting antiviral treatment .
Implantable Cardiac Devices
In patients with implanted defibrillators or pacemakers, chronic administration of antiarrhythmic drugs may affect pacing or defibrillation thresholds. Therefore, at the inception of and during amiodarone treatment, pacing and defibrillation thresholds should be assessed.
CORDARONE may cause fetal harm when administered to a pregnant woman. Fetal exposure may increase the potential for cardiac, thyroid, neurodevelopmental, neurological, and growth effects in neonate .
Chronic administration of CORDARONE may lead to peripheral neuropathy, which may not resolve when CORDARONE is discontinued.
Photosensitivity And Skin Discoloration
CORDARONE induces photosensitization in about 10% of patients; some protection may be afforded sun-barrier creams or protective clothing. During long-term treatment, a blue-gray discoloration of the exposed skin may occur. The risk may be increased in patients of fair complexion or those with excessive sun exposure. Some reversal of discoloration may occur upon drug discontinuation.
Volatile Anesthetic Agents
Patients on CORDARONE therapy may be more sensitive to the myocardial depressant and conduction effects of halogenated inhalational anesthetics.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to inform their prescriber of a known or suspected pregnancy .
Advise women that breastfeeding is not recommended during treatment with CORDARONE .
Advise patients to avoid grapefruit juice and St. John’s Wort.
Advise patients to seek medical attention if they experience the signs and symptoms of pulmonary toxicity, worsening arrhythmia, bradycardia, visual impairment, or hypo- and hyperthyroidism.
This product’s label may have been updated. For full prescribing information, please visit www.pfizer.com.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Amiodarone HCl was associated with a statistically significant, dose-related increase in the incidence of thyroid tumors (follicular adenoma and/or carcinoma) in rats. The incidence of thyroid tumors was greater than control at the lowest dose level tested, i.e., 5 mg/kg/day (approximately 0.08 times the maximum recommended human maintenance dose*).
Mutagenicity studies (Ames, micronucleus, and lysogenic tests) with CORDARONE were negative.
In a study in which amiodarone HCl was administered to male and female rats, beginning 9 weeks prior to mating, reduced fertility was observed at a dose level of 90 mg/kg/day (approximately 1.4 times the maximum recommended human maintenance dose*).
*600 mg in a 60 kg patient (dose compared on a body surface area basis)
Use In Specific Populations
Available data from postmarketing reports and published case series indicate that amiodarone use in pregnant women may increase the risk for fetal adverse effects including neonatal hypo- and hyperthyroidism, neonatal bradycardia, neurodevelopmental abnormalities, preterm birth and fetal growth restriction. Amiodarone and its metabolite, desethylamiodarone (DEA), cross the placenta. Untreated underlying arrhythmias, including ventricular arrhythmias, during pregnancy pose a risk to the mother and fetus (see Clinical Considerations). In animal studies, administration of amiodarone to rabbits, rats, and mice during organogenesis resulted in embryofetal toxicity at doses less than the maximum recommended human maintenance dose (see Data). Advise pregnant women of the potential risk to a fetus.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%-4% and 15%-20%, respectively.
Disease-Associated Maternal And Or Embryo/Fetal Risk
The incidence of ventricular tachycardia is increased and may be more symptomatic during pregnancy. Ventricular arrhythmias most often occur in pregnant women with underlying cardiomyopathy, congenital heart disease, valvular heart disease, or mitral valve prolapse. Most tachycardia episodes are initiated by ectopic beats and the occurrence of arrhythmia episodes may therefore, increase during pregnancy due to the increased propensity to ectopic activity. Breakthrough arrhythmias may also occur during pregnancy, as therapeutic treatment levels may be difficult to maintain due to the increased volume of distribution and increased drug metabolism inherent in the pregnant state.
Fetal/Neonatal Adverse Reactions
Amiodarone and its metabolite have been shown to cross the placenta. Adverse fetal effects associated with maternal amiodarone use during pregnancy may include neonatal bradycardia, QT prolongation, and periodic ventricular extrasystoles, neonatal hypothyroidism (with or without goiter) detected antenatally or in the newborn and reported even after a few days of exposure, neonatal hyperthyroxinemia, neurodevelopmental abnormalities independent of thyroid function, including speech delay and difficulties with written language and arithmetic, delayed motor development, and ataxia, jerk nystagmus with synchronous head titubation, fetal growth restriction, and premature birth. Monitor the newborn for signs and symptoms of thyroid disorder and cardiac arrhythmias.
Labor And Delivery
Risk of arrhythmias may increase during labor and delivery. Patients treated with CORDARONE should be monitored continuously during labor and delivery .
In pregnant rats and rabbits during the period of organogenesis, amiodarone HCl in doses of 25 mg/kg/day (approximately 0.4 and 0.9 times, respectively, the maximum recommended human maintenance dose*) had no adverse effects on the fetus. In the rabbit, 75 mg/kg/day (approximately 2.7 times the maximum recommended human maintenance dose*) caused abortions in greater than 90% of the animals. In the rat, doses of 50 mg/kg/day or more were associated with slight displacement of the testes and an increased incidence of incomplete ossification of some skull and digital bones; at 100 mg/kg/day or more, fetal body weights were reduced; at 200 mg/kg/day, there was an increased incidence of fetal resorption. (These doses in the rat are approximately 0.8, 1.6 and 3.2 times the maximum recommended human maintenance dose*) Adverse effects on fetal growth and survival also were noted in one of two strains of mice at a dose of 5 mg/kg/day (approximately 0.04 times the maximum recommended human maintenance dose*).
*600 mg in a 60 kg patient (doses compared on a body surface area basis)
Amiodarone and one of its major metabolites, DEA, are present in breastmilk at between 3.5% and 45% of the maternal weightadjusted dosage of amiodarone. There are cases of hypothyroidism and bradycardia in breastfed infants, although it is unclear if these effects are due to amiodarone exposure in breastmilk. Breastfeeding is not recommended during treatment with CORDARONE .
Females And Males Of Reproductive Potential
Based on animal fertility studies, CORDARONE may reduce female and male fertility. It is not known if this effect is reversible. .
The safety and effectiveness of CORDARONE in pediatric patients have not been established.
Normal subjects over 65 years of age show lower clearances and increased drug half-life than younger subjects . In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
- Presents as hypersensitivity pneumonitis or interstitial/alveolar pneumonitis (10-17% incidence with 400 mg/day)
- May present without symptoms as abnormal diffusion capacity in a much higher percentage of patients
- Fatal in ~10% of cases
- Common but usually mild and evidenced only by abnormal liver enzymes
- Overt liver disease can occur and has been fatal in a few cases
- Like other antiarrhythmics, can exacerbate the arrhythmia (eg, by making the arrhythmia less well tolerated or more difficult to reverse)
- 2-5% incidence; includes significant heart block or sinus bradycardia
- Manage arrhythmias in proper clinical setting
- Effects are prolonged when they occur because of long drug half-life
Severe sinus node dysfunction, 2°/3° AV block or bradycardia causing syncope (except with functioning artificial pacemaker), cardiogenic shock
Avoid during breastfeeding
To be administered only by physicians experienced in treatment of life-threatening arrhythmias, who are thoroughly familiar with risks and benefits of amiodarone therapy, and have access to facilities adequate for monitoring effectiveness and side effects of treatment; because of long half-life of amiodarone and its metabolite desethylamiodarone, the potential for adverse reactions or interactions, as well as observed adverse effects, can persist following amiodarone withdrawal
Adjust dosage based on adverse reaction and therapeutic response
Avoid excessive exposure to sunlight; may cause photosensitivity
Attempts to substitute other antiarrhythmic agents when amiodarone must be stopped is difficult due to the complex pharmacokinetics of the drug, including prolonged duration of action and half-life and difficulties predicting them, which in turn increases risk for drug interactions
Hypothyroidism has been reported in 2 to 10% of patients receiving amiodarone and may be primary or subsequent to resolution of preceding amiodarone-induced hyperthyroidism; manage hypothyroidism by reducing the dose of or discontinuing amiodarone and considering the need for thyroid hormone supplement
Risks of acute MI, AV block, cardiomegaly; especially with IV administration
Bradycardia and atrio-ventricular block reported; treat bradycardia by slowing infusion rate or discontinuing therapy; in some patients, inserting a pacemaker is required; treat patients with a known predisposition to bradycardia or AV block in a setting where a temporary pacemaker is available
Hypotension is the most common adverse reaction; in some cases, hypotension may be refractory and result in a fatal outcome; treat hypotension initially by slowing the infusion; additional standard therapy may include vasopressor drugs, positive inotropic agents, and volume expansion; monitor initial rate of infusion closely, not to exceed recommended rate
Chronic administration of antiarrhythmic drugs may affect defibrillation or pacing thresholds in patients with implanted defibrillators, pacemakers; assess when therapy is initiated and throughout
Correct hypokalemia, hypomagnesemia or hypocalcemia before initiating treatment 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, systemic corticosteroids, amphotericin B (IV) or other drugs affecting electrolyte levels
May increase risks of pulmonary fibrosis; liver disease; hypotension, bradycardia, hyperthyroidism; optic neuropathy; pleural effusion; pneumonitis (including eosinophilic pneumonia); consider alternative antiarrhythmic therapy if patient experiences signs or symptoms of pulmonary toxicity; prednisone 40 to 60 mg/day tapered over several weeks may be helpful in treating pulmonary toxicity
Acute-onset (days to weeks) pulmonary injury reported in patients treated with IV amiodarone; findings have included pulmonary infiltrates and masses on X-ray, bronchospasm, wheezing, fever, dyspnea, cough, hemoptysis, and hypoxia; some cases have progressed to respiratory failure or death
Postoperatively, occurrences of adult respiratory distress syndrome reported in patients receiving amiodarone therapy who have undergone either cardiac or noncardiac surgery; although patients usually respond well to vigorous respiratory therapy, in rare instances the outcome has been fatal; until further studies performed, monitor FiO2 and determinants of oxygen delivery to tissues (e.g., SaO2, PaO2) while taking amiodarone
Use caution when administering concomitantly with drugs that prolong QTc interval
Corneal microdeposits appear in majority of adults treated; usually discernible only by slit-lamp examination, but give rise to symptoms such as visual halos or blurred vision up to 10% of patients; corneal microdeposits are reversible upon reduction of dose or termination of treatment; asymptomatic microdeposits alone are not reason to reduce dose or discontinue treatment
Causes increased INR; use caution when initiating therapy in patients treated with warfarin
Close perioperative monitoring is recommended in patients undergoing general anesthesia who are on amiodarone therapy as they may be more sensitive to myocardial depressant and conduction effects of halogenated inhalational anesthetics
Fatal cutaneous reactions reported, including Stevens-Johnson syndrome and toxic epidermal necrolysis; discontinue therapy if symptoms of progressive skin rash occur
Monitor hepatic enzymes regularly in patients receiving relatively high maintenance doses; asymptomatic elevations of hepatic enzyme levels seen frequently, but therapy can cause life-threatening hepatic injury; histology has resembled that of alcoholic hepatitis or cirrhosis; obtain baseline and periodic liver transaminases; if transaminases exceed three times normal, or doubles in a patient with an elevated baseline, discontinue or reduce dose, obtain follow-up tests and treat appropriately
Peripheral neuropathy reported rarely with chronic administration; may resolve upon discontinuation of therapy
Bradycardia, some requiring pacemaker insertion reported when ledipasvir/sofosbuvir or sofosbuvir with simeprevir initiated in patients on amiodarone; bradycardia generally occurred within hours to days, but in some cases up to 2 weeks after initiating antiviral treatment; monitor heart rate in patients taking or recently discontinuing amiodarone when starting antiviral treatment
Drug interaction overview
- Serious symptomatic bradycardia when co-administered with ledipasvir/sofosbuvir or with sofosbuvir with simeprevir; postmarketing cases of symptomatic bradycardia, some requiring pacemaker insertion and at least one fatal, have been reported when ledipasvir/sofosbuvir or sofosbuvir with simeprevir were initiated in patients on amiodarone; bradycardia generally occurred within hours to days, but in some cases up to 2 weeks after initiating antiviral treatment and resolved after discontinuation of antiviral treatment; monitor heart rate in patients taking or recently discontinuing amiodarone when starting antiviral treatment
- Concomitant use of drugs with depressant effects on sinus and AV node (e.g., digoxin, beta blockers, verapamil, diltiazem, ivabradine, clonidine) can potentiate electrophysiologic and hemodynamic effects of amiodarone, resulting in bradycardia, sinus arrest, and AV block; monitor heart rate in patients on amiodarone and concomitant drugs that slow heart rate
Cordarone X 150 mg/3 ml Solution for Injection
Amiodarone injection contains benzyl alcohol (20 mg/ml). Benzyl alcohol may cause toxic reactions and allergic reactions in infants and children up to 3 years old.
The administration of medications containing benzyl alcohol to newborns or premature neonates has been associated with a fatal “Gasping Syndrome” (symptoms include a striking onset of gasping syndrome, hypotension, bradycardia and cardio-vascular collapse). As benzyl alcohol may cross the placenta, solution for injection should be used with caution in pregnancy.
Cordarone X Intravenous should only be used in a special care unit under continuous monitoring (ECG and blood pressure).
IV infusion is preferred to bolus due to the haemodynamic effects sometimes associated with rapid injection (see section 4.8). Circulatory collapse may be precipitated by too rapid administration or overdosage (atropine has been used successfully in such patients presenting with bradycardia).
Do not mix other preparations in the same syringe. Do not inject other preparations in the same line. If Cordarone X should be continued, this should be via intravenous infusion (see section 4.2).
Repeated or continuous infusion via peripheral veins may lead to injection site reactions (see section 4.8). When repeated or continuous infusion is anticipated, administration by a central venous catheter is recommended.
When given by infusion Cordarone X may reduce drop size and, if appropriate, adjustments should be made to the rate of infusion.
Anaesthesia (see section 4.5):
Before surgery, the anaesthetist should be informed that the patient is taking amiodarone.
Caution should be exercised in patients with hypotension and decompensated cardiomyopathy and severe heart failure (also see section 4.3).
Amiodarone has a low pro-arrhythmic effect. Onsets of new arrhythmias or worsening of treated arrhythmias, sometimes fatal, have been reported. It is important, but difficult to differentiate a lack of efficacy of the drug from a proarrhythmic effect, whether or not this is associated with a worsening of the cardiac condition. Proarrhythmic effects generally occur in the context of QT prolongation factors such as drug interactions and/or electrolytic disorders (see sections 4.5 and 4.8). Despite QT interval prolongation, amiodarone exhibits a low torsadogenic activity.
Too high a dosage may lead to severe bradycardia and to conduction disturbances with the appearance of an idioventricular rhythm, particularly in elderly patients or during digitalis therapy. In these circumstances, Cordarone X treatment should be withdrawn. If necessary, beta-adreno-stimulants or glucagon may be given. Because of the long half-life of amiodarone, if bradycardia is severe and symptomatic the insertion of a pacemaker should be considered.
The pharmacological action of amiodarone induces ECG changes: QT prolongation (related to prolonged repolarisation) with the possible development of U-waves and deformed T-waves; these changes do not reflect toxicity.
Severe bradycardia (see section 4.5):
Cases of severe, potentially life-threatening bradycardia and heart block have been observed when amiodarone is used in combination with sofosbuvir in combination with another hepatitis C virus (HCV) direct acting antiviral (DAA), such as daclatasvir, simeprevir, or ledipasvir. Therefore, coadministration of these agents with amiodarone is not recommended.
If concomitant use with amiodarone cannot be avoided, it is recommended that patients are closely monitored when initiating sofosbuvir in combination with other DAAs. Patients who are identified as being at high risk of bradyarrhythmia should be continuously monitored for at least 48 hours in an appropriate clinical setting after initiation of the concomitant treatment with sofosbuvir.
Due to the long half-life of amiodarone, appropriate monitoring should also be carried out for patients who have discontinued amiodarone within the past few months and are to be initiated on sofosbuvir alone or in combination with other direct DAAs.
Patients receiving these hepatitis C medicines with amiodarone, with or without other medicines that lower heart rate, should be warned of the symptoms of bradycardia and heart block and should be advised to seek urgent medical advice if they experience them.
Primary graft dysfunction (PGD) post cardiac transplant:
In retrospective studies, amiodarone use in the transplant recipient prior to heart transplant has been associated with an increased risk of PGD.
PGD is a life-threatening complication of heart transplantation the presents as a left, right or biventricular dysfunction occurring within the first 24 hours of transplant surgery for which there is no identifiable secondary cause (see section 4.8). Severe PGD may be irreversible.
For patients who are on the heart transplant waiting list, consideration should be given to use an alternative antiarrhythmic drug as early as possible before transplant.
Endocrine disorders (see section 4.8):
Amiodarone IV may induce hyperthyroidism, particularly in patients with a personal history of thyroid disorders or patients who are taking/have previously taken oral amiodarone. Serum usTSH level should be measured when thyroid dysfunction is suspected.
Amiodarone contains iodine and thus may interfere with radio-iodine uptake. However, thyroid function tests (free-T3, free-T4, usTSH) remain interpretable. Amiodarone inhibits peripheral conversion of levothyroxine (T4) to triiodothyronine (T3) and may cause isolated biochemical changes (increase in serum free-T4, free-T3 being slightly decreased or even normal) in clinically euthyroid patients. There is no reason in such cases to discontinue amiodarone treatment if there is no clinical or further biological (usTSH) evidence of thyroid disease.
Respiratory, thoracic and mediastinal disorders (see section 4.8):
Onset of dyspnoea or non-productive cough may be related to pulmonary toxicity such as interstitial pneumonitis. Very rare cases of interstitial pneumonitis have been reported with intravenous amiodarone. When the diagnosis is suspected, a chest X-ray should be performed. Amiodarone therapy should be re-evaluated since interstitial pneumonitis is generally reversible following early withdrawal of amiodarone, and corticosteroid therapy should be considered (see section 4.8). Clinical symptoms often resolve within a few weeks followed by slower radiological and lung function improvement. Some patients can deteriorate despite discontinuing Cordarone X. Fatal cases of pulmonary toxicity have been reported.
Very rare cases of severe respiratory complications, sometimes fatal, have been observed usually in the period immediately following surgery (adult acute respiratory distress syndrome); a possible interaction with a high oxygen concentration may be implicated (see sections 4.5 and 4.8).
Hepatobiliary disorders (see section 4.8):
Severe hepatocellular insufficiency may occur within the first 24 hours of IV amiodarone and may sometimes be fatal. Close monitoring of transaminases is therefore recommended as soon as amiodarone is started.
Severe bullous reactions:
Life-threatening or even fatal cutaneous reactions Stevens-Johnson syndrome (SJS), Toxic Epidermal Necrolysis (TEN) (see section 4.8). If symptoms or signs of SJS, TEN (e.g. progressive skin rash often with blisters or mucosal lesions) are present amiodarone treatment should be discontinued immediately.
Eye disorders (see section 4.8):
If blurred or decreased vision occurs, complete ophthalmologic examination including fundoscopy should be promptly performed. Appearance of optic neuropathy and/or optic neuritis requires amiodarone withdrawal due to the potential progression to blindness.
Drug interactions (see section 4.5):
Concomitant use of amiodarone with the following drugs is not recommended; beta-blockers, heart rate lowering calcium channel inhibitors (verapamil, diltiazem), stimulant laxative agents which may cause hypokalaemia.
Increased plasma levels of flecainide have been reported with co-administration of amiodarone. The flecainide dose should be reduced accordingly, and the patient closely monitored.