左甲状腺素的半衰期长(1 周),因此应在初始治疗或剂量改变后的 4-6 周内检测 TSH 水平。[1]Franklyn JA. Hypothyroidism. Medicine. 2005;33:27-29.[5]Roberts CG, Ladenson PW. Hypothyroidism. Lancet. 2004;363:793-803.http://www.ncbi.nlm.nih.gov/pubmed/15016491?tool=bestpractice.com[13]American Association of Clinical Endocrinologists; American Thyroid Association. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. 2012. http://www.aace.com (last accessed 18 May 2017).https://www.aace.com/files/final-file-hypo-guidelines.pdf 对血清 TSH 水平正常且病情稳定的患者,应每 12 个月测量一次 TSH。[1]Franklyn JA. Hypothyroidism. Medicine. 2005;33:27-29.[13]American Association of Clinical Endocrinologists; American Thyroid Association. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. 2012. http://www.aace.com (last accessed 18 May 2017).https://www.aace.com/files/final-file-hypo-guidelines.pdf 妊娠会增加甲状腺激素的需求,左甲状腺素的所需剂量可能也会相应升高。妊娠期患者应每 6 周测量一次 TSH。[5]Roberts CG, Ladenson PW. Hypothyroidism. Lancet. 2004;363:793-803.http://www.ncbi.nlm.nih.gov/pubmed/15016491?tool=bestpractice.com