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Liothyronine is a synthetic form of thyroid hormone (T3) used to treat hypothyroidism and myxedema coma. It is also used as an augmentation strategy in treating Major Depressive Disorder when used in combination with antidepressants.〔(【引用サイトリンク】url=http://ajp.psychiatryonline.org/article.aspx?articleid=178261#B38 )〕 It is marketed as the sodium salt under the brand name Cytomel (or Tertroxin in Australia). ==Uses== Physicians can use this instead of or in addition to levothyroxine (T4) for patients undergoing thyroid withdrawal. When a patient has thyroid cancer or Graves' disease, ablation therapy with radioactive iodine (131I) can be used to remove any trace thyroid tissue. For 131I therapy to be effective, the trace thyroid tissue must be avid to iodine. The best method is to starve the tissue of iodine but this can lead to hypothyroid symptoms for the patient. Withdrawal from levothyroxine can be done but it takes six weeks of withdrawal for the remaining thyroid tissue to be completely starved. Six weeks is needed owing to levothyroxine's long half life. Six weeks can be inconvenient for the patient and delay treatment. Liothyronine instead can be taken and withdrawn from for two weeks to starve the thyroid tissue. This is much safer and more convenient than levothyroxine. Also, due to its quicker onset of action when compared to levothyroxine, it sometimes is a better option in patients with myxedema coma or in patients preparing for 133I therapy for thyroid cancer.〔http://pharmacistanswers.com/hypothyroidism-medications.html〕 Low-dose liothyronine has been shown to improve depression symptoms in patients with normal thyroid function who do not have adequate relief from their depression after trying several different antidepressants. When added to existing medications, liothyronine helped achieve remission in 24% of patients participating in a subset of the large STAR *D depression trial. According to a 2001 meta-analysis that analyzed the effectiveness of adding Liothyronine to tricyclic antidepressants, women in particular may benefit from Liothyronine. The average effective dose for depression was 45 mcg of Liothyronine daily, which is lower than the doses used for treating hypothyroidism.〔 About 9% of patients stopped taking liothyronine due to side effects.〔 The difference in gender response may be due to differences in metabolism of thyroid precursors. An algorithm developed from the STAR *D trial recommends liothyronine as an option when patients have failed two antidepressant medications. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Liothyronine」の詳細全文を読む スポンサード リンク
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