Thyrotoxicosis

Muller AF, Berghout A, Wiersinga WM, Kooy A, Smits JW, Hermus AR, Anonymous00181. · Diakonessenhuis Utrecht, Utrecht, the Netherlands. · Neth J Med. · Pubmed #18349473 links to  free full text

Abstract: Thyroid function disorders are common with a female to male ratio of 4 to 1. In adult women primary hypothyroidism and thyrotoxicosis have a prevalence of 3.5/1000 and 0.8/1000, respectively. This guideline is aimed at secondary care providers especially internists, but also contains relevant information for interested general practitioners and gynaecologists. A multidisciplinary working group, containing delegates of professional and patient organisations, prepared the guideline. According to principles of 'evidence-based medicine' available literature was studied and discussed. Considering the availability and quality of published studies a practical advice was formulated. For a full overview of the literature and considerations the reader is referred to the original version of the guideline (accessible through NIV-net). In this manuscript we have aimed to provide the practicing internist with practical and 'as evidence-based as possible' treatment guidelines with respect to thyroid function disorders.

Razvi S, Basu A, McIntyre EA, Wahid ST, Bartholomew PH, Weaver JU, Anonymous00365. · Department of Diabetes and Endocrinology, Queen Elizabeth Hospital, Gateshead, Tyne and Wear, UK. · Nucl Med Commun. · Pubmed #15208494 No free full text.

Abstract: BACKGROUND: Thyrotoxicosis is associated with significant morbidity, therefore adequate control of the disease is paramount. The outcome of treatment of thyrotoxicosis using radioiodine shows variable failure rates depending, amongst other things, on the administered activity of radioiodine and the use of anti-thyroid drugs. Thus, management should follow an evidence based protocol, which has a low failure rate. METHOD: We prospectively analysed the outcome of treatment using our Gateshead protocol of a fixed administered activity of radioiodine therapy (400 MBq) given to 201 patients (including 140 with Graves' disease, 48 with toxic multinodular goitre (TMNG) and 13 with toxic nodule) followed up for a median period of 12 months (range, 6-77 months). Carbimazole was discontinued in patients rendered euthyroid 16 days prior to radioiodine. No routine anti-thyroid drugs or thyroxine were given following radioiodine unless hypothyroidism or thyrotoxicosis occurred. RESULTS: Following the Gateshead protocol led to a failure rate of 6.5% (eight females with Graves' disease, four females with TMNG and one female with toxic nodule), 29% euthyroidism and 64% hypothyroidism. The rates of hypothyroidism for women and for men were: in Graves' disease 77% and 79%, in TMNG 29% and 75%, in toxic nodule 42% and 0%, respectively. CONCLUSIONS: Our observations show that withholding an antithyroid drug in excess of just over 2 weeks prior to administering a fixed administered activity of radioiodine in patients with thyrotoxicosis leads to the lowest reported failure rate, irrespective of the underlying cause. One possible mechanism for this could be the avoidance of drug induced radio-resistance.

van der Molen AJ, Thomsen HS, Morcos SK, Anonymous00275. · Department of Radiology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. · Eur Radiol. · Pubmed #14997334 No free full text.

Abstract: Excess free iodide in the blood (ingested or injected) may cause thyrotoxicosis in patients at risk. Iodinated contrast medium solutions contain small amounts of free iodide and may be of significance for patients at risk. The free iodide may also interfere with nuclear medicine diagnostic studies and treatment. Therefore the Contrast Media Safety Committee of the European Society of Urogenital Radiology reviewed the literature on this subject in order to prepare guidelines. A report and guidelines were prepared based on an extensive Medline search. The report was discussed with the participants attending the Tenth European Symposium on Urogenital Radiology, Uppsala, Sweden, September 2003. Contrast medium induced thyrotoxicosis is rare. Contrast medium injection does not affect thyroid function tests (e.g., T3, T4, TSH) in patients with a normal thyroid. Routine monitoring of thyroid function tests before contrast medium injection in patients with a normal thyroid is not indicated even in areas where there is dietary iodine deficiency. Patients at risk of developing thyrotoxicosis after contrast medium injection are patients with Graves' disease and patients with multinodular goiter with thyroid autonomy, especially elderly patients and patients living in areas of iodine deficiency. Patients at high-risk should be carefully monitored by endocrinologists after contrast medium examinations. Prophylaxis in these groups is not generally recommended, although it may offer some protection in selected high-risk individuals. The free iodide load of contrast media injections interferes with iodide uptake in the thyroid and therefore compromises diagnostic thyroid scintigraphy and radio-iodine treatment of thyroid malignancies for 2 months after administration of contrast media. Simple guidelines on the subject are proposed.

Boppidi H, Daram SR. · No affiliation provided · South Med J. · Pubmed #19139704 No free full text.

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Puente Vázquez J, González Larriba JL. · No affiliation provided · Clin Transl Oncol. · Pubmed #17403622 No free full text.

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Lien YH. · No affiliation provided · Crit Care Med. · Pubmed #17130706 No free full text.

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Tang SW. · No affiliation provided · Hong Kong Med J. · Pubmed #16912349 links to  free full text

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Papi G. · No affiliation provided · Recenti Prog Med. · Pubmed #16499167 No free full text.

Abstract: Overt thyrotoxicosis is defined as elevated serum free thyroxine (FT4) and free triiodothyronine (FT3), and suppressed thyrotropin (TSH) concentrations. Thyrotoxicosis with TSH suppression only (TTSO), and normal thyroid hormone concentrations, is also defined as mild thyrotoxicosis. Both overt thyrotoxicosis and TTSO may be caused by the same thyroid disorders. The most common cause of thyrotoxicosis is the use of excessive doses of L-thyroxine for the treatment of hypothyroidism, non-toxic goiter or thyroid carcinoma (exogenous thyrotoxicosis). Less commonly, the cause of thyrotoxicosis is endogenous. The endogenous thyrotoxicosis may be due to either overproduction and release of thyroid hormones from the gland with normal/high 24-hour thyroid radioiodine uptake (e.g., Graves disease and toxic nodular goiter), or release of excess thyroid hormones due to follicle disruption with low/absent 24-hour thyroid radioiodine uptake (e.g., sub-acute de Quervain thyroiditis). The present report briefly reviews the current problems regarding the clinical and therapeutical approach to thyrotoxicosis, and in particular the TTSO.

Zyśko D, Gajek J. · Katedra i Klinika Kardiologii Akademii Medycznej we Wrocławiu. · Pol Merkur Lekarski. · Pubmed #15518416 No free full text.

Abstract: In this study three problems concerning interactions between thyroid and cardiovascular system are discussed. Cardiac arrhythmias, congestive heart failure, pleural effusion, hyperlipidaemia, arterial hypertension may be consequences of thyroid disorders leading to inappropriate hormone secretion. During such illnesses as heart failure, myocardial infarction and in patients undergoing coronary artery bypass surgery profound changes may occur in thyroid hormone metabolism known as sick euthyroid syndrome. Treatment with amiodarone may lead to changes in thyroid tests results and to development of hypothyroidism or thyrotoxicosis.

Owen PJ, Lazarus JH. · No affiliation provided · J Endocrinol Invest. · Pubmed #12841533 No free full text.

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Peiris AN. · No affiliation provided · South Med J. · Pubmed #12539985 No free full text.

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Ptácek LJ. · No affiliation provided · J Clin Endocrinol Metab. · Pubmed #12414842 links to  free full text

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Hashizume K. · No affiliation provided · Intern Med. · Pubmed #10852157 links to  free full text

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Gough I, Meyer-Witting M. · No affiliation provided · Aust N Z J Surg. · Pubmed #10765894 No free full text.

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Lévy S. · No affiliation provided · Eur Heart J. · Pubmed #10653670 links to  free full text

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Stockigt JR. · No affiliation provided · Med J Aust. · Pubmed #10474600 No free full text.

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McDougall IR. · No affiliation provided · Nucl Med Commun. · Pubmed #10404524 No free full text.

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Gallagher EJ. · No affiliation provided · J Emerg Med. · Pubmed #9950400 No free full text.

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O'Doherty MJ, McElhatton PR, Thomas SH. · No affiliation provided · BMJ. · Pubmed #9872862 links to  free full text

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Agbaht K, Bitik B, Piskinpasa S, Bayraktar M, Topeli A. · Department of Internal Medicine, Endocrinology and Metabolism Unit, Ankara University Faculty of Medicine, Sihhiye, Ankara, Turkey. · Int J Clin Pharmacol Ther. · Pubmed #19473592 No free full text.

Abstract: BACKGROUND: Ciprofloxacin-associated seizures (CAS) occur most commonly in patients with special risk factors that may cause accumulation of drug (high doses of the drug, old age, renal insufficiency, drug interactions) or that may decrease the threshold of epileptogenic activity (electrolyte abnormalities, history of seizures, electroconvulsive therapy). OBJECTIVE: To report thyrotoxicosis as a risk factor previously not heralded for the development of CAS. CASE SUMMARY: A 24-year-old woman was admitted to the hospital because of convulsions, severe myopathy, and acute renal failure after taking ciprofloxacin for sinusitis, and urinary tract infections. Prior to ciprofloxacin ingestion, she had no seizure history, was not receiving any other medication, and her routine laboratory results including creatinine and electrolytes were within normal ranges. Electroencephalogram suggested epileptiform waves. Cranial magnetic resonance imaging was normal. Further laboratory examinations documented thyrotoxicosis in association with postpartum thyroiditis. DISCUSSION: In the reviewed literature, all cases of CAS occurred in the presence of at least one risk factor for CAS. CONCLUSIONS: CAS appear to be restricted to individuals with predisposing risk factors, therefore it is always necessary to search such fact. When a physician encounters the possibility of CAS, in addition to previously described risk factors, thyrotoxicosis should also be considered in the differential diagnosis. Further, in patients with untreated thyrotoxicosis, antibiotics other than ciprofloxacin might be preferable for therapy.

Saito J, Nishikawa T. · Department of Endocrinology and Metabolism, Internal Medicine, Yokohama Rosai Hospital. · Nippon Rinsho. · Pubmed #19432125 No free full text.

Abstract: Childhood thyroid hormone (T3) is essential for the normal development of endochondral and intramembranous bone and plays an important role in the linear growth and maintenance of bone mass. In adult, T3 stimulates osteoclastic bone resorption mediated primarily by TR alpha and local conversion by deiodinase D2 may play a role in local activation. TSH seems to be an inhibitor of bone resorption and formation. In thyrotoxicosis patients with Graves' disease, there is increased bone remodelling, characterized by an imbalance between bone resorption and formation, which results in a decrease of bone mineral density (BMD) and an increased risk for osteoporotic fracture. Antithyroid treatment is able to reduce dramatically the bone resorption and to normalize BMD reduction. But previous hyperthyroidism is independently associated with an increased risk for fracture. Although further studies relating to the mechanism for possible impaired bone strength in these patients will be needed, bisphosphonates may be beneficial treatment for prevention of bone fractures in patients with severe risk for fractures, such as post-menopausal women.

Friedlander AH, Yoshikawa TT, Chang DS, Feliciano Z, Scully C. · VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA. · J Am Dent Assoc. · Pubmed #19188413 No free full text.

Abstract: BACKGROUND: Atrial fibrillation (AF) is a cardiac rhythm disturbance arising from disorganized electrical activity in the atria, and it is accompanied by an irregular and often rapid ventricular response. It is the most common clinically significant dysrhythmia in the general and older population. TYPES OF STUDIES REVIEWED: The authors conducted a MEDLINE search using the key terms "atrial fibrillation," "epidemiology," "pathophysiology," "treatment" and "dentistry." They selected contemporaneous articles published in peer-reviewed journals and gave preference to articles reporting randomized controlled trials. CLINICAL IMPLICATIONS: The anticoagulant warfarin frequently is prescribed to prevent stroke caused by cardiogenic thromboemboli arising from stagnant blood in poorly contracting atria. Most dental procedures and a limited number of surgical procedures can be performed without altering warfarin dosage if the international normalized ratio value is within the therapeutic range of 2.0 to 3.0. Certain analgesic agents, antibiotic agents, antifungal agents and sedative hypnotics, however, should not be prescribed without consultation with the patient's physician because these medications may alter the patient's risk of hemorrhage and stroke. CONCLUSIONS: AF affects nearly 2.5 million Americans, most of who are older than 60 years. Consultation with the patient's physician to discuss the planned dental treatment often is appropriate, especially for people who frequently have comorbid diseases such as coronary artery disease, congestive heart failure, diabetes and thyrotoxicosis, which are treated with multiple drug regimens.

Gärtner R. · Medizinische Klinik Innenstadt der Universität München. · Dtsch Med Wochenschr. · Pubmed #19142837 No free full text.

Abstract: Thyroid disorders may not only be the cause infertility but also increases the incidence of miscarriages and the morbidity of the pregnancies. During pregnancy the demand of thyroid hormones increases to about 30 - 50 % and the thyroid has to cope with this increase. In Germany the iodine intake has improved significantly during the last 20 years, but still is borderline low with an mean intake of about 120 microg iodide per day. Therefore it is still recommended that pregnant women are supplemented with about 100 - 150 microg of iodide during pregnancy and the time of breast-feeding, to avoid hypothyroidism of the foetus with concomitant delay of the brain development. Not only women with subclinical hypothyroidism, but only elevated TPO antibodies have a significant increase in early miscarriage and preterm delivery. An early supplementation with Levothyroxin despite euthyroidism might reduce these risks. Those women also more frequently develop postpartum thyroiditis. This risk can be reduced by a supplementation with selenium during and after pregnancy. Graves' disease is a rare disorder and only about 0,1 - 0,4 pregnancies are affected. The course of the disease is biphasic, with an exacerbation within the first trimester and an improvement thereafter, but a recurrence after delivery. Overt thyrotoxicosis has to be treated with propylthiouracil, to maintain euthyroidism during pregnancy. The TSH receptor antibodies are transferred to the foetus with the risk of thyrotoxicosis. Special care of the foetus is therefore necessary. Transient mild hyperthyroidism may occur in women with very high HCG levels during the first three months of pregnancy. This often is associated with hyperemesis gravidarum. Subclinical hypothyroidism of the mother will disturb the normal development of the foetus and therefore has to be treated even when TSH is within the upper normal level. Special care is necessary in women with elevated TPO antibodies, because these more often develop postpartum thyroiditis.

Motohashi K, Sakai R, Hagihara M, Enaka M, Kanamori H, Maruta A, Ishigatsubo Y. · Department of Hematology, Kanagawa Cancer Center, Japan. · Rinsho Ketsueki. · Pubmed #19110527 No free full text.

Abstract: We describe a 44-year-old man with acute myelogenous leukemia who developed thyrotoxicosis after unrelated cord blood transplantation. He complained of fever, general fatigue, tremor and tachycardia on day 63. On examination of thyroid function, free triiodothyronine (23.67 pg/ml) and free thyroxine (5.71 ng/dl) were increased, and thyroid-stimulating hormone (<0.03 microU/ml) was decreased. Antithyroid receptor antibody, antithyroid peroxidase antibody and antithyroglobulin antibody were all negative. The patient was diagnosed as having thyrotoxicosis. His symptoms improved and thyroid function returned to the normal levels within 2 weeks. Thyrotoxicosis is a rare complication, but we should be aware that it may cause idiopathic fever after stem cell transplantation.

Shindo M. · Division of Otolaryngology-Head and Neck Surgery, State University of New York at Stony Brook, Stony Brook, NY, USA. · ORL J Otorhinolaryngol Relat Spec. · Pubmed #18971594 No free full text.

Abstract: Surgical treatment of hyperthyroidism requires an understanding of the pathophysiology of thyrotoxicosis and of differentiating hyperthyroidism from non-hyperthyroid causes of thyrotoxicosis. The surgeon must determine or confirm the etiology of the patient's hyperthyroidism for surgical planning and ensure that surgery is indicated. Furthermore, preoperative preparation with appropriate medication is essential for minimizing intraoperative and postoperative complications. This chapter outlines the differential diagnosis of thyrotoxicosis, preoperative evaluation and preparation for surgery.