Abstract:
The synthetic retinoid bexarotene (BXT), used in the treatment of cutaneous T-cell lymphoma (CTCL), has been associated with central hypothyroidism due to suppression of thyrotropin (TSH) secretion and upregulation of peripheral thyroxine (T4) and triiodothyronine (T3) metabolism. We present a case of a 41-year-old man with CTCL who developed central hypothyroidism within 1 month of receiving BXT. He required sequential uptitration of levothyroxine (LT4) over 15 months, and free T4 (FT4) and total T3 levels were normalized by a daily regimen of LT4 600 mcg and liothyronine (LT3) 15 mcg. While almost all patients regain normal hypothalamic-pituitary-thyroid axis function after cessation of BXT, there are limited data regarding LT4 and LT3 dosing required to adequately treat central hypothyroidism in patients on BXT. Our patient required an LT4 dose approximately 2.8 times the calculated weight-based dose and LT3 supplementation, demonstrating a large LT4/LT3 combination dose may be required to compensate for BXT-induced central hypothyroidism.
摘要:
合成类维生素A贝沙罗汀(BXT),用于治疗皮肤T细胞淋巴瘤(CTCL),由于促甲状腺激素(TSH)分泌的抑制以及外周甲状腺素(T4)和三碘甲状腺原氨酸(T3)代谢的上调,因此与中枢甲状腺功能减退有关。我们介绍了一例41岁的CTCL患者,他在接受BXT后1个月内出现了中枢甲状腺功能减退症。他需要在15个月内连续增加左甲状腺素(LT4),游离T4(FT4)和总T3水平通过LT4600mcg和利塞罗宁(LT3)15mcg的每日方案进行标准化。虽然几乎所有患者在停止BXT后恢复正常的下丘脑-垂体-甲状腺轴功能,关于充分治疗BXT患者的中枢甲状腺功能减退症所需的LT4和LT3剂量的数据有限.我们的患者需要的LT4剂量约为计算的基于体重的剂量和LT3补充的2.8倍,可能需要大量LT4/LT3组合剂量来补偿BXT诱导的中枢甲状腺功能减退症.