warfarin and Graves-Disease

Cerebral venous sinus thrombosis usually occurs in patients with a precipitating condition such as thrombophilic disorders, pregnancy or due to medications, such as oestrogens. Some case reports have reported the co-occurrence of cerebral venous sinus thrombosis in patients with hyperthyroidism. However, the association of cerebral venous sinus thrombosis with hyperthyroidism remains contentious. We present the case of a patient who presented with a clinical picture of cerebral venous sinus thrombosis with no obvious precipitating factor. Further investigations revealed the presence of hyperthyroidism due to Graves' disease, which was thought to be the provocative disorder for cerebral venous sinus thrombosis. We would like to draw the attention of clinicians to a possible causative association between cerebral venous sinus thrombosis and hyperthyroidism.

Topics: Adrenergic beta-Antagonists; Adult; Anticoagulants; Antithyroid Agents; Carbimazole; Computed Tomography Angiography; Enoxaparin; Graves Disease; Humans; Magnetic Resonance Imaging; Male; Phlebography; Propranolol; Sinus Thrombosis, Intracranial; Warfarin

The article describes a case of Graves' disease treated with methimazole and examines the influence of methimazole-induced alterations of thyroid hormone concentrations during warfarin therapy. A 22-year-old woman presented at our endocrinology outpatient clinic with palpitations, sweating, fatigue, tremors, and diarrhea. She had a pain in her right leg and had difficulty walking. Her thyroid profile was consistent with hyperthyroidism. The patient was treated with warfarin 5 mg once a day for deep vein thrombosis for 2 days. Since a therapeutic range of International Normalized Ratio levels could not be achieved, methimazole was stopped due to drug-drug interaction. Lithium was started instead. A euthyroid state was obtained in 2 weeks together with a therapeutic International Normalized Ratio level. Interactions between warfarin and drugs that alter thyroid hormone concentrations have been reported; however, the extent and significance of the interaction between methimazole and warfarin have been inadequately described. Concomitant therapy with warfarin and antithyroid drugs should be managed by frequent monitoring of both thyroid function and the International Normalized Ratio. Lithium is employed only to provide temporary control of thyrotoxicosis in patients who cannot take thionamide and iodide. The administration of lithium alone or in combination with other drugs is shown to be an effective method of controlling hyperthyroidism when conventional antithyroid drugs show adverse effects or become insufficient. When warfarins are used together with antithyroid medications, adequate anticoagulation may not be obtained due to drug-drug interactions. Lithium can be an alternative drug for antithyroid medication in patients on warfarin therapy.

Topics: Adult; Anticoagulants; Antithyroid Agents; Drug Interactions; Female; Graves Disease; Humans; International Normalized Ratio; Lithium Carbonate; Methimazole; Thyroid Hormones; Warfarin

To describe a case of Graves' disease treated with methimazole and examine the influence of thyroid hormone alteration on warfarin anticoagulation.. A 54-year-old man presented to the emergency department with palpitations, fatigue, weight loss, and anxiety attacks. He was taking no medications at that time. An electrocardiogram showed new onset atrial fibrillation. His thyroid profile was consistent with hyperthyroidism. The patient was admitted to the intensive care unit and started on methimazole 30 mg/day, metoprolol, enoxaparin, and warfarin 5 mg/day. Postdischarge doses of warfarin and methimazole were adjusted over the next several months based on thyroid panel results indicative of hypothyroidism. Postdischarge changes in methimazole dose caused alterations in thyroid function and intensity of anticoagulation as measured by international normalized ratio.. Interactions between warfarin and drugs that alter thyroid hormone concentrations have been reported; however, the extent and significance of the interaction between methimazole and warfarin have been inadequately described. Thyroid hormone concentrations influence the metabolic rates of proteins and, thus, can alter the amount of vitamin K-dependent clotting factors, which in turn can alter the extent of inhibition by warfarin. This may lead to changes in the intensity of anticoagulation and thereby increase the risk of thromboembolic or hemorrhagic events.. Changes in thyroid hormone concentrations have the potential to significantly alter the extent of warfarin-induced anticoagulation. Clinicians must be aware of the need for close anticoagulation monitoring and dosage adjustment in patients receiving concomitant warfarin and methimazole. The full extent of this interaction may be delayed following a change in methimazole dose.

Topics: Anticoagulants; Antithyroid Agents; Drug Interactions; Electrocardiography; Graves Disease; Humans; Male; Methimazole; Middle Aged; Thyroid Function Tests; Thyroid Hormones; Warfarin

A 39 year-old man was admitted to our hospital because of severe headache with fever continuing over two weeks. Three days after admission he developed aphasia and right hemiparesis, when his CT revealed subarachnoid hemorrhage at the left sylvian fissure. He was diagnosed as suffering from cerebral venous thrombosis because empty delta sign was positive on the enhanced brain CT. Suprasagittal sinus and bilateral transverse sinuses were not detected on the cerebral angiography. He was also diagnosed as having Graves' disease for the first time on the basis of free T3 13.56 pg/ml, free T4 4.65 ng/dl, TSH < 0.01 IU/ml, anti-TSH receptor antibody 4.3 IU/l, and thyroid stimulating antibody 224%. On the examination, homocystine and activities of antithrombin III, protein C, and protein S were normal. Antinculear, anti-DNA, anti-Sm, anticardiolipin beta2GP-I antibodies, and PR3ANCA were negative. Factor VIII activity, however, markedly increased over 300%, which has been known to increase in the cases of hyperthyroidism. He recovered well after the treatment with thiamazole in addition to warfarin followed by intravenous heparin. There are only six cases of cerebral venous thrombosis due to hyperthyroidism with increased factor VIII level. All of those cases were female, and 5 of them were taking oral contraceptives. This is a first Japanese male case.

Topics: Adult; Anticoagulants; Antithyroid Agents; Factor VIII; Female; Graves Disease; Humans; Intracranial Thrombosis; Male; Methimazole; Thrombophilia; Treatment Outcome; Warfarin

We report the case of a 48-year-old woman with a diagnosis of pulmonary hypertension and hyperthyroidism (Graves' disease) in whom pulmonary artery pressures became normal after treatment of thyroid disease. The possible pathogenic mechanisms involved in this association include the presence of hyperdynamic heart failure and/or the presence of immune alterations underlying both conditions.

Topics: Anticoagulants; Antithyroid Agents; Autoimmunity; Cardiotonic Agents; Digitalis Glycosides; Female; Graves Disease; Humans; Hypertension, Pulmonary; Hyperthyroidism; Middle Aged; Spain; Warfarin

A 31-year old cook suffered from episodes with muscular weakness since 3 weeks. These episodes resolved, at times, spontaneously and completely after a few hours. The weakness affected mainly the muscles of trunk and proximal extremities. Investigation of the patient revealed flaccid tetraparesis with diminished tendon reflexes, however, cranial muscles were not affected. Mental function and sensibility were intact. These findings were consistent with hypopotassemic periodic paralysis rather than a neurological or psychiatric disease. Serum potassium was determined as 1.8 mmol/l. Moreover, the patient suffered from atrial fibrillation. Grave's disease could be identified as the underlying cause of hypopotasemic periodic paralysis and atrial fibrillation. Further manifestations of primary hyperthyroidism were nervousness, diarrhea and weight loss of 5 kg observed during the previous months. The symptoms resolved under treatment with potassium, betablocker and thyrostatic agents. The patient was treated with warfarin because of atrial fibrillation and finally underwent electroconversion.

Topics: Adrenergic beta-Antagonists; Adult; Anticoagulants; Atrial Fibrillation; Diagnosis, Differential; Electric Countershock; Graves Disease; Humans; Hypokalemia; Male; Muscle Weakness; Potassium; Time Factors; Warfarin

Topics: Aged; Aircraft; Anticoagulants; Aspirin; Diabetes Complications; Female; Graves Disease; Humans; Pulmonary Embolism; Risk Factors; Syndrome; Travel; Venous Thrombosis; Warfarin