Influence of anticonvulsants and flunarizine on the metabolism of thyroid hormones: speculation about the possible role of calmodulin.
Interference of anticonvulsants with the metabolism of hormones may lead to side effects. Anticonvulsants influence the hypothalamic-pituitary-thyroid axis, in that lowering of thyrotropin [thyroid-stimulating hormone (TSH)] and thyroxine levels is observed. In the present study, flunarizine, a calcium ion blocker, administered as add-on medication, further lowered serum thyroxine but not TSH. The underlying biochemical principle may be an interference with the mediation of signals by calcium-calmodulin at the level of the thyroid follicle.
D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology* / Q000627:therapeutic use; D002147:Calmodulin / Q000494:pharmacology*; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D005444:Flunarizine / Q000494:pharmacology*; D006801:Humans; D008297:Male; D013963:Thyroid Hormones / Q000378:metabolism*
D000927:Anticonvulsants; D002147:Calmodulin; D013963:Thyroid Hormones; D005444:Flunarizine