Endocrinology (R.V., G.S., F.T., S.B.), Department of Clinical and Experimental Medicine University of Messina, 98125 Messina, Italy; Master Program on Childhood, Adolescence and Women's Endocrine Health (S.B.), University of Messina, 98125 Messina, Italy; and Interdepartmental Program of Molecular and Clinical Endocrinology and Women's Endocrine Health (S.B.), A.O.U. Policlinico G. Martino, 98125 Messina, Italy.
J Clin Endocrinol Metab. 2014 Dec;99(12):4481-6. doi: 10.1210/jc.2014-2684.
Proton-pump inhibitors (PPIs) impair tablet levothyroxine (LT4) intestinal absorption by increasing the gastric pH and decreasing LT4 dissolution in the stomach.
The purpose of this study was to verify whether a liquid formulation of LT4 would correct LT4 malabsorption induced by PPIs.
This was a prospective observational cohort study. The study was conducted from 2012 to 2013, and the mean duration of the follow-up was 23.7 ± 11.9 weeks.
The study was conducted in a tertiary university hospital outpatients clinic.
Upon informed consent, we recruited 24 consecutive adult patients (18 women and 6 men), who took LT4 for replacement (n = 14) or suppressive purposes (n = 10) and who had absorption of tablet LT4 impaired by PPIs.
The 24 patients were switched from the tablet to the oral solution LT4 at the same daily dose.
Significantly lower mean TSH levels were seen with the oral solution than with the tablet as were significantly greater rates of serum TSH less than or equal to the specified cutoff values (replacement [REP] group) or ≤ 0.10 mU/L (suppressive [SUP] group) with the oral solution than with the tablet.
Serum TSH was lower with the oral solution than with the tablet formulation (REP group, 1.7 ± 1.0 mU/L vs 5.4 ± 4.3, P < .0001; SUP group, 0.1 ± 0.3 mU/L vs 2.1 ± 2.7, P < .0001). In the REP group, the rate of TSH values of ≤ 4.12 or ≤ 2.5 mU/L was 29 of 30 (96.7%) or 24 of 30 (80.0%) postswitch but only 17 of 36 (47.2%) or 9 of 36 (25.0%) preswitch (P < .0001). In the SUP group, the rate of serum TSH values of ≤ 0.10 mU/L was 26 of 35 (74.3%) postswitch but 0 of 22 (0%) preswitch (P < .0001).
These data demonstrate the continued absorption of liquid LT4 despite the increased gastric pH due to PPI therapy.
质子泵抑制剂（PPIs）通过增加胃 pH 值和减少胃中 LT4 的溶解来降低片剂左甲状腺素（LT4）的肠道吸收。
本研究旨在验证 LT4 的液体剂型是否可以纠正由 PPIs 引起的 LT4 吸收不良。
这是一项前瞻性观察队列研究。该研究于 2012 年至 2013 年进行，平均随访时间为 23.7±11.9 周。
该研究在一所三级大学医院的门诊进行。
在知情同意的情况下，我们招募了 24 名连续服用 LT4 进行替代（n=14）或抑制（n=10）治疗且因 PPIs 而导致 LT4 片剂吸收不良的成年患者。
24 名患者从 LT4 片剂转换为口服溶液，剂量相同。
与片剂相比，口服溶液的平均 TSH 水平显著降低，并且口服溶液的血清 TSH 低于或等于规定截止值（替代[REP]组）或≤0.10 mU/L（抑制[SUP]组）的比率显著更高。
与片剂相比，口服溶液的血清 TSH 水平更低（REP 组，1.7±1.0 mU/L 与 5.4±4.3，P<.0001；SUP 组，0.1±0.3 mU/L 与 2.1±2.7，P<.0001）。在 REP 组中，TSH 值≤4.12 或≤2.5 mU/L 的比率为 30 例中的 29 例（96.7%）或 30 例中的 24 例（80.0%）转换后，但只有 36 例中的 17 例（47.2%）或 36 例中的 9 例（25.0%）转换前（P<.0001）。在 SUP 组中，血清 TSH 值≤0.10 mU/L 的比率为 35 例中的 26 例（74.3%）转换后，但转换前的 22 例中没有 0 例（0%）（P<.0001）。
这些数据表明，尽管由于 PPI 治疗导致胃 pH 值升高，但液体 LT4 的吸收仍在继续。
