Medications and thyroid function: complex interactions
Résumé
Numerous drugs can interfere with the synthesis, the secretion, the metabolism or the hypothalamic-pituitary regulation of thyroid hormones. Effects were demonstrated with formerly used drugs but it is not clear, because of the lack of data, if the effect is a class effect. The clinical effect is sometimes significant and to be known in order to adapt treatment (bexarotene, sunitinib, sorafenib, intestinal absorption inhibitors, estrogens), but most of the time effects are not important in the euthyroid patient. The impact of drugs can lead subclinical hypothyroid patients towards clinical hypothyroidism, and, in hypothyroid treated patients, a biological control is necessary to adapt the levothyroxine doses. The impact of these drugs may lead to misinterpretation of biological data, and a control before additional explorations or treatment is useful, the effect of numerous drugs being transient, with a return to a normal state by adaptation of the hypothalamo-pituitary axis.