Thyroid storm

Peripheral Antagonists. The relatively long duration of action of the thyroid hormones makes it desirable to have compounds capable of blocking them competitively at their site of action. This is desirable in the treatment of thyroid storm where the reduction of circulating hormone levels brought about by the inhibition of their synthesis is too slow. 

Large doses of iodide inhibit the synthesis and release of thyroid hormones. Serum T4 levels may be reduced within 24 hours, and the effects may last for 2 to 3 weeks. Iodides are used most commonly in Graves disease patients prior to surgery and to quickly reduce hormone release in patients with thyroid storm. Potassium iodide is administered either as a saturated solution (SSKI) that contains 38 mg iodide per drop or as Lugol s solution, which contains 6.3 mg iodide per drop. The typical starting dose is 120 to 400 mg/day. Iodide therapy should start 7 to 14 days prior to surgery. Iodide should not be... 

Blockers have been used widely to ameliorate thyrotoxic symptoms such as palpitations, anxiety, tremor, and heat intolerance. They have no effect on peripheral thyrotoxicosis and protein metabolism and do not reduce TSAb or prevent thyroid storm. Propranolol and nadolol partially block the conversion of T4 to T3, but this contribution to the overall therapeutic effect is small. 

Blockers are usually used as adjunctive therapy with antithyroid drugs, RAI, or iodides when treating Graves disease or toxic nodules in preparation for surgery or in thyroid storm. /3-Blockers are primary therapy only for thyroiditis and iodine-induced hyperthyroidism. 

Drug Dosages Used in the Management of Thyroid Storm... 

Corticosteroids are generally recommended, but there is no convincing evidence of adrenocortical insufficiency in thyroid storm their benefits may be attributed to their antipyretic action and stabilization of blood pressure. 

Thyrotoxicosis -adrenergic blockers may mask clinical signs (eg, tachycardia) of developing or continuing hyperthyroidism. Abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm. 

III.b.1.4. lodinated contrast media. When iodides or thioamides are contraindicated, the contrast media ipodate and iopanoic acid may be used to treat hyperthyroidism. These drugs rapidly inhibit conversion of T4 to T3 in the liver, kidney, brain and pituitary gland, and the effects are so rapid that they are sometimes helpful in the treatment of thyroid storm (see below). The drugs are non toxic and have prolonged effect. Precautions are similar to iodide,... 

Pretreatment with antithyroid drugs is necessary to avoid the risk of thyroid storm (exacerbation of hyperthyroidism with fever and tachycardia) in the following groups the elderly, people with cardiac disease, and people with severe hyperthyroidism. Antithyroid drugs should be stopped at least 4 days before radioactive iodine is given, and restarted no sooner than 3 days after, to permit uptake of the iodine into the thyroid gland. Antithyroid drugs can usually be stopped after 2-6 weeks as the radioactive iodine takes effect. 

Occasionally patients develop a dramatically acute and severe form of thyrotoxicosis which may be life-threatening, termed thyroid crisis or thyroid storm. In this condition the patient is at risk of cardiac complications, notably arrhythmia and ventricular failure, and it requires very urgent treatment. It is essential to use high doses of anti-thyroid drugs, and PTU is often preferred for this, particularly because of its fast absorption. Iodides or ipodate are often... 

Thyrotoxic crisis, thyroid storm, or accelerated hyperthyroidism is an extreme accentuation of thyrotoxicosis. Although uncommon, this serious complication of hyperthyroidism usually occurs in association with Grave s disease and occasionally with toxic multinodular goiter. 

Acebufolol adminisfration may precipitate CHF or MI in patients with heart disease thyroid storm in those with thyrotoxicosis or peripheral ischemia in those with existing peripheral vascular disease. 

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