Division of Endocrinology, University of Ottawa, Ottawa, ON, Canada.
Int J Gen Med. 2013 Apr 29;6:335-9. doi: 10.2147/IJGM.S43494. Print 2013.
"The pseudomalabsorption of thyroxine" has been used to describe patients with hypothyroidism who fail to comply with their treatment. We describe a unique case of a 32-year-old with hypothyroidism who developed pituitary hyperplasia and hyperprolactinemia secondary to the pseudomalabsorption of thyroxine.
After baseline thyroid-function tests were performed, the patient was administered levothyroxine 0.5 mg under the supervision of a registered nurse. Thyroid function testing was repeated at 30, 60, 120, and 180 minutes. Arrangements were made for further daily supervised loading of levothyroxine 0.1 mg.
With the administration of 0.5 mg levothyroxine, free thyroxine levels increased by 120 minutes, and with daily supervised dosing of 0.1 mg there was normalization of the thyroid hormone levels and a reduction of thyroid-stimulating hormone levels. Maintenance of thyroid-stimulating hormone < 15 mU/L for 2 weeks led to a reduction in prolactin levels and regression in the size of the pituitary on magnetic resonance imaging.
If left untreated, these patients face significant morbidity and are at risk of developing pituitary hyperplasia, complications from an increase in pituitary size, hyperprolactinemia, and potentially myxedema coma. Recognizing pituitary hyperplasia and hyperprolactinemia as a complication from the pseudomalabsorption of levothyroxine may prevent the potential of a misdiagnosis of a prolactinoma leading to unnecessary investigations and inappropriate treatment. Patient awareness of this serious complication and the rapid, demonstrable resolution with adequate thyroid hormone replacement may provide motivation to comply with supervised dosing of levothyroxine. It has also been suggested that supervised treatment enables the individual to maintain their patient status, which may be in part the motivation behind this disorder.
“甲状腺素假性吸收”一词曾被用来描述未能遵医嘱治疗的甲状腺功能减退症患者。我们描述了一例独特的病例，一名 32 岁的甲状腺功能减退症患者因甲状腺素假性吸收而继发垂体增生和高催乳素血症。
进行基线甲状腺功能检查后，在注册护士的监督下给予患者左甲状腺素 0.5mg。在 30、60、120 和 180 分钟时重复进行甲状腺功能检查。安排进一步每天监督服用左甲状腺素 0.1mg。
给予 0.5mg 左甲状腺素后，游离甲状腺素水平在 120 分钟时升高，每天监督给予 0.1mg 左甲状腺素可使甲状腺激素水平正常化，并降低促甲状腺激素水平。促甲状腺激素维持<15mU/L 2 周可降低催乳素水平并使垂体磁共振成像上的大小缩小。
如果不治疗，这些患者会出现明显的发病率，并面临垂体增生、垂体增大相关并发症、高催乳素血症以及潜在的黏液水肿昏迷的风险。认识到甲状腺素假性吸收引起的垂体增生和高催乳素血症可能会防止误诊为催乳素瘤，从而避免不必要的检查和不适当的治疗。患者对这种严重并发症的认识，以及充足的甲状腺激素替代治疗可迅速、明显地解决问题，可能会激发患者的遵医嘱治疗动机。有人提出，监督治疗可以使患者维持其患者状态，这可能是这种疾病的部分动机。
