Amiodarone toxicity occurs in about 23% of patients. He subsequently reverted to sinus rhythm and his medication was stopped 1 year prior. For those living in iodinedepleted areas, the incidence is higher 10%. Clinical course and predictors of outcome david conen, ludovic melly, christoph kaufmann, stefan bilz, peter ammann, beat schaer, christian sticherling, beat muller, stefan osswald this study evaluated the clinical course and predictors of longterm outcome in 84 patients with amiodarone induced thyrotoxicosis ait. In this study we aimed to assess amiodarone s effects on thyroid hormones, c reactive protein crp, interleukin 6 il6 and tumor necrosis factor tnf. Amiodarone induced thyrotoxicosis can occur in either of two forms, type 1 or type 2, depending on whether there was a positive history of thyroid dysfunction prior to the use of amiodarone therapy or not, respectively. A 69yearold man presented with a 6week history of shortness of breath on exertion, unintentional weight loss, altered bowel habits and lethargy. A unique underlying pathophysiology discerns one type from another, which is why early. Successful treatment of amiodaroneinduced thyrotoxicosis. Ptu for the treatment of amiodaroneinduced thyrotoxicosis.
The former results from the inability of the thyroid to escape from the wolffchaikoff effect. Amiodaroneinduced hyperthyroidism endocrinology jama. Amiodarone induced hyperthyroidism assessment of the predictive value of biochemical testing and response to combined therapy using propylthiouracil and potassium perchlorate. Newnham hh, topliss dj, le grand ba, chosich n, harper rw, stockigt jr. Background amiodaroneinduced thyrotoxicosis ait is a difficult management problem about which there are little published data. Treatment of amiodaroneassociated thyrotoxicosis medscape.
Methimazole mmi and potassium perchlorate kclo 4 is the treatment of choice for the former, whereas corticosteroids are used for the latter. We discuss the medical management of ait and anesthetic considerations for management of patients with thyrotoxicosis. Thyroid dysfunction is an important sideeffect of amiodarone therapy. However, mixed forms appear frequently and it is not easy to. Amiodarone induced thyrotoxicosis ait is a complex therapeutic challenge.
Amiodaroneinduced thyrotoxicosis and thyroid cancer. Treatment of amiodarone induced thyrotoxicosis is difficult since the drug. Amiodaroneinduced thyrotoxicosis develops in 3% of amiodarone treated patients. Amiodarone induced toxic nodular goiter, a form of iodine induced thyrotoxicosis, was described in europe where large nodular goiters are more prevalent than in the united states. A stepwise approach to the treatment of amiodaroneinduced. Among 12 thyrotoxic patients, a patient with arrhythmogenic right. Amiodarone induced thyrotoxicosis ait is a clinical condition fraught with difficulties and uncertainties both from the diagnostic and therapeutic standpoints. Management of amiodaronerelated thyroid problems ncbi. Amiodarone cordarone induced hyperthyroidism can be found in up to 12 percent of treated patients, especially those in iodinedeficient areas, and occurs by two mechanisms. Amiodaroneinduced thyroid dysfunction has been reported to affect 224% of users. Full paper evaluation of 99mtcmibi in thyroid gland imaging for the diagnosis of amiodarone induced thyrotoxicosis junqi wang and. We examined whether continuing amiodarone or differentiating ait into 2 subtypes. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Nov 29, 2006 amiodaroneinduced thyrotoxicosis ait develops in 3% of amiodaronetreated patients in north america.
Jun 29, 2002 siralthough amiodarone is viewed as a highly effective antiarrythmic agent, its use may lead to alterations in thyroid gland function, thyroid hormone metabolism, or both more than rarely. Amiodaroneinduced thyrotoxicosis the journal of clinical. Reintroduction of amiodarone in patients with a history of amiodarone induced thyrotoxicosis ait is rarely used. A new study provides evidence that glucocorticoid therapy is safe, effective and. Management of severe amiodaroneinduced thyrotoxicosis after. He subsequently reverted to sinus rhythm and his medication was stopped 1 year prior to presentation. Amiodarone associated thyrotoxicosis occurs in 610% of people given the drug and is. Amiodarone induced thyrotoxicosis ait develops in 3% of amiodarone treated patients in north america. Thyroid unit and department of medicine, massachusetts general hospital. Pdf thyroid hormones and proinflammatory cytokines. We report a case of a man who underwent a total thyroidectomy for metastatic follicular thyroid cancer who required amiodarone. Amiodarone induced thyrotoxicosis thyroid disease manager. Available in pdf format for saving and printing and web page format for viewing online. To the best of our knowledge this is the first reported case of this condition.
In europe, amiodaroneinduced hyperthyroidism aih is more frequent than hypothyroidism, occurring in up to 10% of patients treated with amiodarone. However, mixed forms appear frequently and it is not easy to prescribe corticosteroids because of side effects. Amiodarone can lead to both hypothyroidism amiodarone induced hypothyroidism and less commonly hyperthyroidism amiodarone induced thyrotoxicosis and relates to high iodine content within the molecule as well as to several unique intrinsic properties of amiodarone. Based on the differences in their pathological and physiological mechanisms, many methods have been developed so far to differentiate ait subtypes such as colour flow doppler sonography cfds and 24h radioiodine uptake raiu. Amiodarone, a benzofuranic iodinerich antiarrhythmic drug, causes thyroid dysfunction in 1520% of cases. Radioiodine ablation of the thyroid to allow the reintroduction of amiodarone treatment in patients with a prior history of amiodarone induced. Treatment of amiodaroneinduced thyrotoxicosis, a diffkult challenge. This is a condition called type i amiodarone induced thyrotoxicosis hyperthyroidism. Amiodarone induced thyrotoxicosis is a predictor of adverse cardiovascular outcome. Thyroiditis is a condition that may be suitable for management in the general practice setting. Use of glucocorticoids in amiodaroneinduced thyrotoxicosis. Both ait and aih may develop either in appar ently normal thyroid. Although amiodaroneinduced hypothyroidism poses no particular problem, amiodaroneinduced thyrotoxicosis ait is a diagnostic and therapeutic challenge.
Type 1 ait is characterized by increased thyroid hormone synthesis due to iodine. He was diagnosed with atrial fibrillation 2 years previously and started on amiodarone and warfarin. When surgical treatment is planned for patients with a solitary thyroid nodule and amiodarone induced hyperthyroidism, preoperative thyroid scanning will direct the surgeon to perform either subtotal thyroidectomy for diffuse disease or lobectomy for a hyperfunctioning nodule. Amiodarone, thyroid dysfunction, thyrotoxicosis, hy. We discuss the medical management of ait and anesthetic considerations for management of patients with thyrotoxicosis and. Despite antithyroid drug therapy, some patients demonstrated refractory hyperthyroidism. Evaluation of 99mtcmibi in thyroid gland imaging for the diagnosis of amiodarone induced thyrotoxicosis. Amiodarone induced thyrotoxicosis recurrence after amiodarone reintroduction. Clinical course and predictors of outcome david conen, ludovic melly, christoph kaufmann, stefan bilz, peter ammann, beat schaer, christian sticherling, beat muller, stefan osswald this study evaluated the clinical course and predictors of longterm outcome in 84 patients with amiodaroneinduced thyrotoxicosis ait. Amiodaroneinduced thyrotoxicosis ait develops in 3% of amiodaronetreated patients in north america. Two types of amiodarone induced thyrotoxicosis are recognized, designated type 1 and type 2, based on whether or not the patient had a preexisting thyroid disorder. Associated with worsening cardiac arrhythmia with recurrence of atrial fibrillation and palpitations ncbi amiodarone induced thyrotoxicosis may occur suddenly in patients treated with amiodarone for several years, likely due to its long half life, lipid solubility and accumulation in almost all tissue.
Oct 08, 2018 however, a metaanalysis suggested that with the lower doses of amiodarone 150330 mg incidence of thyroid dysfunction is 3. The adverse effects of amiodarone may be seen months after discontinuation because its long halflife 107 days. Amiodarone hydrochloride, an iodinerich drug used in the treatment of tachyarrhythmias, is responsible for the development of thyrotoxicosis in approximately 10% of patients who reside in areas of moderate iodine deficiency. Amiodaroneinduced thyroid dysfunction in clinical practice.
Amiodarone can cause hyperthyroidism and hypothyroidism. Amiodarone is an iodinerich drug widely used for the management of various cardiac arrhythmias and severe congestive heart failure. Algorithm for the management of amiodaroneinduced thyrotoxicosis ait. Methods and results the type and duration of antithyroid treatment and response were recorded in a consecutive series of 28 cases. Amiodaroneinduced toxic nodular goiter, a form of iodineinduced thyrotoxicosis, was described in europe where large nodular goiters are more prevalent than in the united states.
Background amiodarone, an iodinerich medication used to treat abnormal heart rhythms, can result in thyrotoxicosis in 15% of patients. Type 1 ait occurs in patients with underlying thyroid pathology such as autonomous nodular goiter or graves disease. Amiodarone induced thyrotoxicosis ait occurs in 3% of all the patients treated and is subclassified into type 1 and 2. A new study provides evidence that glucocorticoid therapy is safe, effective and associated with prompt restoration. Amiodaroneinduced thyrotoxicosis ait is a clinical condition that is notoriously difficult to manage. Lithium treatment in amiodaroneinduced thyrotoxicosis. Type 1 occurs in patients with underlying thyroid pathology such as autonomous nodular goiter, graves disease or hashimotos thyroiditis. Patients treated with amiodarone may manifest altered thyroid hormone profile without thyroid dysfunction, or they may present with clinically significant amiodarone induced hypothyroidism or amiodarone induced thyrotoxicosis.
However, amiodarone is associated with a number of side effects, including thyroid dysfunction both hypo and hyperthyroidism, which is due to amiodarones high iodine content and its direct toxic effect on the thyroid. We examined whether continuing amiodarone or differentiating ait into 2 subtypes affected outcome. Amiodaroneinduced thyrotoxicosis develops in 3% of amiodaronetreated patients. Surgical management of amiodaroneinduced thyrotoxicosis. Amiodaroneinduced thyrotoxicosis associated with thyrotropin. Amiodaroneinduced thyrotoxicosis with cardiopulmonary. Proportion of type 1 and type 2 amiodarone induced thyrotoxicosis has changed over a 27year period in italy.
The incidence of type 2 amiodarone induced thyrotoxicosis ait is increasing. Patients should have their thyroid function tested prior to starting amiodarone. Background amiodaroneinduced thyrotoxicosis is a condition that is dif. Members of the european thyroid association eta with clinical interests were asked to answer a questionnaire on the diagnosis and management. The effects range from abnormal thyroid function test findings to overt thyroid dysfunction, which may be either amiodarone induced thyrotoxicosis ait or amiodarone induced hypothyroidism aih. Amiodaroneinduced thyrotoxicosis with cardiopulmonary arrest. Racgp evaluating and managing patients with thyrotoxicosis. The mechanism for amiodaroneinduced hyperthyroidism and. The thyrotoxicosis is mediated by amiodarone s iodine content. Amiodarone induced thyrotoxicosis ait, may occur early after taking the drug, during usage for several years and even long time after withdrawl of the drug because it is stored in tissues and slowly released from them. Amiodarone induced thyrotoxicosis ait is caused by amiodarone as a side effect of cardiovascular disease treatment. Hypotension, bradycardia, ventricular fibrillation, and asystole have been seen in a few people given amiodarone. Evaluation of 99mtcmibi in thyroid gland imaging for the.
In addition, it can also cause type ii amiodarone induced thyrotoxicosis, which occurs from actual thyroid tissue destruction. Amiodarone is used to treat lifethreatening ventricular arrhythmias with an additional offlabel indication for intractable atrial fibrillation. Amiodarone is a heavily iodinated drug used commonly in several forms of arrhythmias. The researchers performed this study to compare the risk of antithyroid drugassociated agranulocytosis in amiodarone induced thyrotoxicosis patients with those who had thyrotoxicosis from other causes. Despite the potential risks of anaesthesia associated with uncontrolled thyrotoxicosis, thyroidectomy should be considered in the setting of life. Ait represents a diagnostic and therapeutic challenge, while aih does not cause critical problems in most cases. Amiodarone induced thryrotoxicosis ait is a rare but serious complication of amiodarone use, especially in patients with severe cardiac disease. Despite the easy management of amiodaroneinduced hypothyroidism, the. The most common form in the united kingdom is type 2 amiodarone induced thyroiditis, and a recent randomised controlled trial found that the most effective treatment for this was prednisolone.
Since amiodarone was first marketed in 1992 in japan, the incidence of amiodarone induced thyrotoxicosis ait has been increasing. Diagnosis and management of thyrotoxicosis the bmj. Anesthetic considerations in a patient with amiodarone. Amiodarone induced thyrotoxicosis ait is well recognized and is generally believed to be due to the excess iodine released from the metabolism of the drug, although amiodarone associated. Pdf context amiodarone induced thyrotoxicosis ait is a difficult diagnostic and management challenge, especially during severe. From the division of medical sciences, university of birmingham, birmingham, uk. Hyperthyroidism is an excessive concentration of thyroid hormones. Apr 02, 2020 thyrotoxicosis is a welldocumented complication of amiodarone treatment, but little has been written about the risks and treatment of recurrent thyrotoxicosis on reexposure to amiodarone.
Type 2 ait is a result of amiodarone causing a subacute thyroiditis with release of preformed thyroid hormones into the circulation. We present a patient who developed ait, following administration of amiodarone for lifethreatening ventricular arrhythmias. To describe the case of a man who developed amiodarone induced thyrotoxicosis ait after a total thyroidectomy for metastatic follicular thyroid cancer because of the effect of the drug on metastasis. Amiodarone restart after amiodaroneinduced thyrotoxicosis. Amiodarone induced thyrotoxicosis is a complex diagnostic and therapeutic challenge. This increase in iodine delivery and uptake can increase thyroid hormone production and release. Although most patients remain clinically euthyroid, a significant minority up to 15% of patients in the uk and the usa develop amiodarone induced hypothyroidism or thyrotoxicosis. To determine how expert european thyroidologists assess and treat amiodarone induced thyrotoxicosis ait. Mar 18, 2020 the major clinical features of the patient were weight loss and deterioration of the underlying cardiovascular symptoms, which are again characteristic of amiodarone induced thyrotoxicosis ait. Dronedarone is a recently approved antiarrhythmic drug. Background amiodarone induced thyrotoxicosis ait is a difficult management problem about which there are little published data. Approach to the patient with amiodaroneinduced thyrotoxicosis. The time lag between initiation of amiodarone treatment.
The thyrotoxicosis is mediated by amiodarones iodine content. Thyrotoxicosis is a relatively uncommon complication of amiodarone treatment found in 10% to 12% of patients residing in iodinedeficient areas1, 2 and with an approximately 3% incidence in the united states. Amiodarone can lead to both hypothyroidism amiodaroneinduced hypothyroidism and less commonly hyperthyroidism amiodaroneinduced thyrotoxicosis and relates to high iodine content within the molecule as well as to several unique intrinsic properties of amiodarone. Amiodarone induced thyrotoxicosis ait is a clinically. It is known to produce thyroid abnormalities ranging from abnormal thyroid function testing to overt hypothyroidism or hyperthyroidism. These adverse effects may occur in patients with or without preexisting thyroid disease. Gross appearance of the thyroid showing homogeneous, beefyred, richincolloid thyroid parenchyma a and 2 welldemarcated, light yellow nodules arrowsb. Amiodarone, thyroid dysfunction, thyrotoxicosis, hypothyroidism. Diagnosis and treatment are closely linked, because the diagnostic problems may affect the therapeutic approach and lead to suboptimal treatment and delayed resolution of dysfunction. Thyroidectomy for amiodaroneinduced thyrotoxicosis jama. Amiodarone, a widely used antiarrhythmic drug, is known to cause thyroid dysfunction, such as amiodarone induced thyrotoxicosis ait and amiodarone induced hypothyroidism aih through its pharmacological and toxic actions 1, 2. However, thyroid tissue is needed in order to develop thyrotoxicosis. Close liaison with a cardiologist is recommended to best manage these patients. Pdf thyroidectomy for amiodarone induced thyrotoxicosis.
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