Larkin J G, Macphee G J, Beastall G H, Brodie M J
University Department of Medicine, Western Infirmary, Glasgow, Scotland, UK.
Eur J Clin Pharmacol. 1989;36(3):213-6. doi: 10.1007/BF00558149.
Anticonvulsants are associated with decreased serum thyroid hormone concentrations. We have studied thyroid function in 54 epileptic patients on a variety of drugs (19 on carbamazepine, 13 on phenytoin, 10 on sodium valproate, 12 on polypharmacy). For comparison, 14 untreated epileptics and 11 healthy unmedicated volunteers were included as controls. Total thyroxine (T4) concentrations were reduced in patients taking enzyme-inducing drugs (carbamazepine and/or phenytoin) compared with both controls and patients taking sodium valproate. Similar differences were shown with each individual drug. All nine patients whose circulating T4 was below the lower limit of the reference range were taking enzyme inducers. Free thyroxine concentrations were also reduced in individuals treated with carbamazepine and phenytoin with five values falling beneath the reference range. Tri-iodothyronine and thyrotropin appeared unaffected by anticonvulsant administration. Thyrotropin releasing hormone stimulation revealed no true hypothyroidism. The lowering effect of anticonvulsant drugs on circulating total and free T4 was not exhibited by the non-inducing sodium valproate. These data support the influence of enzyme induction as a likely mechanism for reduced thyroxine concentrations in treated epileptic patients.
抗惊厥药与血清甲状腺激素浓度降低有关。我们研究了54例服用各种药物的癫痫患者的甲状腺功能（19例服用卡马西平，13例服用苯妥英钠，10例服用丙戊酸钠，12例联合用药）。作为对照，纳入了14例未经治疗的癫痫患者和11例未用药的健康志愿者。与对照组和服用丙戊酸钠的患者相比，服用酶诱导药物（卡马西平和/或苯妥英钠）的患者总甲状腺素（T4）浓度降低。每种药物都显示出类似的差异。所有9例循环T4低于参考范围下限的患者都在服用酶诱导剂。服用卡马西平和苯妥英钠的患者游离甲状腺素浓度也降低，有5个值低于参考范围。三碘甲状腺原氨酸和促甲状腺激素似乎不受抗惊厥药给药的影响。促甲状腺激素释放激素刺激试验未显示真正的甲状腺功能减退。非诱导性丙戊酸钠未表现出抗惊厥药对循环总T4和游离T4的降低作用。这些数据支持酶诱导作用的影响，这可能是治疗癫痫患者甲状腺素浓度降低的机制。
