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The Journal of Clinical Endocrinology... Jan 2001
Review
Topics: Aged; Amiodarone; Animals; Drug Therapy, Combination; Humans; Male; Thyroidectomy; Thyrotoxicosis
PubMed: 11231968
DOI: 10.1210/jcem.86.1.7119 -
The Canadian Journal of Cardiology Jul 2009Amiodarone-induced thyrotoxicosis (AIT) develops in 3% of amiodarone-treated patients in North America. AIT is classified as type 1 or type 2. Type 1 AIT occurs in... (Review)
Review
BACKGROUND
Amiodarone-induced thyrotoxicosis (AIT) develops in 3% of amiodarone-treated patients in North America. AIT is classified as type 1 or type 2. Type 1 AIT occurs in patients with underlying thyroid pathology such as autonomous nodular goiter or Graves' disease. Type 2 AIT is a result of amiodarone causing a subacute thyroiditis with release of preformed thyroid hormones into the circulation.
OBJECTIVES
To review the literature and present an overview of the differentiation between and management of type 1 and type 2 AIT.
METHODS
PubMed, the Cumulative Index to Nursing and Allied Health Literature and Medscape searches of all available English language articles from 1983 to 2006 were performed. Search terms included 'amiodarone -induced thyrotoxicosis', 'complications', 'management', 'treatment' and 'colour flow Dopper sonography'.
RESULTS
There is evidence to suggest that to differentiate between type 1 and type 2 AIT, a careful history and physical examination should be performed to identify pre-existing thyroid disease. An iodine-131 uptake test and colour flow Doppler sonography should be performed. Patients with type 2 AIT should receive a trial of glucocorticoids, whereas those with type 1 should receive antithyroid therapy. For patients in whom the mechanism of the thyrotoxicosis is unclear, a combination of prednisone and antithyroid therapy may be considered.
Topics: Amiodarone; Anti-Arrhythmia Agents; Goiter, Nodular; Graves Disease; Humans; Thyroiditis, Subacute; Thyrotoxicosis; Vasodilator Agents
PubMed: 19584973
DOI: 10.1016/s0828-282x(09)70512-4 -
Acta Clinica Croatica Aug 2022Thyroid gland has a key role in maintaining the body homeostasis. Thyroxine is the main hormone secreted from the thyroid gland, its effect being predominantly achieved... (Review)
Review
Thyroid gland has a key role in maintaining the body homeostasis. Thyroxine is the main hormone secreted from the thyroid gland, its effect being predominantly achieved after the intracellular conversion of thyroxine to triiodothyronine, which exhibits a higher affinity for the receptor complex, thus modifying gene expression of the target cells. Amiodarone is one of the most commonly used antiarrhythmics in the treatment of a broad spectrum of arrhythmias, usually tachyarrhythmias. Amiodarone contains a large proportion of iodine, which is, in addition to the intrinsic effect of the medication, the basis of the impact on thyroid function. It is believed that 15%-20% of patients treated with amiodarone develop some form of thyroid dysfunction. Amiodarone may cause amiodarone-induced hypothyroidism (AIH) or amiodarone-induced thyrotoxicosis (AIT). AIT is usually developed in the areas with too low uptake of iodine, while AIH is developed in the areas where there is a sufficient iodine uptake. Type 1 AIT is more common among patients with an underlying thyroid pathology, such as nodular goiter or Graves' (Basedow's) disease, while type 2 mostly develops in a previously healthy thyroid. AIH is more common in patients with previously diagnosed Hashimoto's thyroiditis. Combined types of the diseases have also been described. Patients treated with amiodarone should be monitored regularly, including laboratory testing and clinical examinations, to early detect any deviations in the functioning of the thyroid gland. Supplementary levothyroxine therapy is the basis of AIH treatment. In such cases, amiodarone therapy quite often need not be discontinued. Type 1 AIT is treated with thyrostatic agents, like any other type of thyrotoxicosis. If possible, the underlying amiodarone therapy should be discontinued. In contrast to type 1 AIT, the basic pathophysiological substrate of which is the increased synthesis and release of thyroid hormones, the basis of type 2 AIT is destructive thyroiditis caused by amiodarone, desethylamiodarone as its main metabolite, and an increased iodine uptake. Glucocorticoid therapy is the basis of treatment for this type of disease.
Topics: Humans; Amiodarone; Thyroxine; Hypothyroidism; Thyrotoxicosis; Thyroiditis; Iodine
PubMed: 36818930
DOI: 10.20471/acc.2022.61.02.20 -
BMJ Case Reports Jan 2021The authors present a case of a 55-year-old gentleman with a medical history of atrial fibrillation on amiodarone who presented with weight loss, palpitations and...
The authors present a case of a 55-year-old gentleman with a medical history of atrial fibrillation on amiodarone who presented with weight loss, palpitations and exertional dyspnoea. Thyroid function tests revealed thyrotoxicosis with a free thyroxine (T4) of 117 pmol/L and a thyroid-stimulating hormone (TSH) of <0.008 mIU/L. Interleukin-6 level was low. The negative TSH-receptor antibody status, the presence of a small thyroid gland with heterogeneous echotexture and decreased internal vascularity on ultrasound together with the relatively quick drop in free T4 and free tri-iodothyronine (T3) levels once prednisolone therapy was added to carbimazole suggested that this was typical of amiodarone-induced thyrotoxicosis (AIT) type 2. Subsequently, carbimazole was discontinued and treatment with prednisolone was continued. This case highlights that AIT management may be challenging and it is of paramount importance to establish the type of AIT present as this will guide management and is key to improving prognosis.
Topics: Amiodarone; Anti-Arrhythmia Agents; Atrial Fibrillation; Humans; Male; Middle Aged; Thyrotoxicosis
PubMed: 33419749
DOI: 10.1136/bcr-2020-238145 -
The Canadian Journal of Neurological... May 2022
Topics: Chorea; Dyskinesias; Humans; Thyrotoxicosis; Upper Extremity
PubMed: 34134800
DOI: 10.1017/cjn.2021.136 -
European Heart Journal. Cardiovascular... Feb 2022
Topics: Humans; Myocarditis; Thyrotoxicosis
PubMed: 34669942
DOI: 10.1093/ehjci/jeab218 -
Hospital Medicine (London, England :... Feb 1999Thyrotoxicosis generally presents with classic signs and symptoms in younger people. Among the elderly population atypical presentation is recognized, although this has... (Review)
Review
Thyrotoxicosis generally presents with classic signs and symptoms in younger people. Among the elderly population atypical presentation is recognized, although this has not been well quantified or characterized. To avoid misdiagnosis or delay in diagnosis, clinical suspicion needs to remain high.
Topics: Aged; Aged, 80 and over; Algorithms; Female; Humans; Long-Term Care; Male; Thyrotoxicosis; Thyrotropin
PubMed: 10320841
DOI: 10.12968/hosp.1999.60.2.1808 -
The American Journal of Emergency... Jan 2021Cervical artery dissection is a rare but important diagnosis to consider in young patients presenting with stroke. Multiple etiologies of cervical artery dissections...
Cervical artery dissection is a rare but important diagnosis to consider in young patients presenting with stroke. Multiple etiologies of cervical artery dissections have been previously reported, but the association with thyrotoxicosis is extremely rare. A previously healthy 43-year-old female presented to the emergency department with new symptoms related to thyrotoxicosis and bilateral internal carotid artery dissections. Her atrial fibrillation and hypertension resolved by treating the underlying hyperthyroidism with methimazole and propranolol. The bilateral internal carotid artery dissections were managed conservatively with acetylsalicylic acid. Despite an initially poor prognosis, the patient made a complete recovery with resolution of her neurological symptoms.
Topics: Adult; Carotid Artery, Internal, Dissection; Female; Humans; Thyrotoxicosis
PubMed: 32646762
DOI: 10.1016/j.ajem.2020.06.025 -
Cleveland Clinic Journal of Medicine Jan 2003Thyrotoxicosis is associated with increased cardiovascular morbidity and mortality, primarily due to heart failure and thromboembolism. However, its signs and symptoms... (Review)
Review
Thyrotoxicosis is associated with increased cardiovascular morbidity and mortality, primarily due to heart failure and thromboembolism. However, its signs and symptoms may be subtle and can easily be missed. Therefore, one should suspect thyrotoxicosis in patients with palpitations, exercise intolerance, dyspnea on exertion, and other cardiovascular signs.
Topics: Adrenergic beta-Antagonists; Amiodarone; Antithyroid Agents; Calcium Channel Blockers; Cardiovascular Diseases; Contrast Media; Humans; Thyrotoxicosis
PubMed: 12549727
DOI: 10.3949/ccjm.70.1.57 -
Nigerian Journal of Medicine : Journal... 2001Thyroid hormone has effects on both the peripheral circulation and the myocardium. These include a decline in the systemic vascular resistance and an increase in cardiac... (Review)
Review
Thyroid hormone has effects on both the peripheral circulation and the myocardium. These include a decline in the systemic vascular resistance and an increase in cardiac output and cardiac contractility. Exposure to excess thyroid hormone, as occurs in thyrotoxicosis, can not only aggravate preexisting cardiac disease but also by itself lead to cardiac disease. More patients are being reported with thyrotoxicosis in Nigeria while the facilities for diagnosis and treatment are improving and becoming more available. There should therefore be a greater awareness of the cardiac problems associated with thyrotoxicosis, especially atrial fibrillation and cardiac failure. Initial management of heart disease in thyrotoxicosis should focus on the prompt alleviation of hyperthyroidism combined with judicious use of diuretics, digoxin and beta-blockers.
Topics: Cardiac Output; Catecholamines; Heart Diseases; Humans; Myocardial Contraction; Nigeria; Thyroid Hormones; Thyrotoxicosis; Vascular Resistance
PubMed: 11705057
DOI: No ID Found