title: The effect of phenobarbital on serum hormone levels and their diurnal variations in pregnancy.
abstract: The effect of phenobarbital (PB) on serum hormones in late pregnancy was investigated. 18 pregnant women were studied before and after 2 weeks of PB treatment (100 mg per os, daily at 8 p.m.) by measuring serum estradiol, estriol, progesterone, testosterone, prolactin and cortisol concentrations. 7 pregnant women without PB therapy served as controls. Estradiol levels in the morning decreased, whereas those of estriol increased both in the morning and evening during PB treatment. The estriol/estradiol ratio increased in women on PB. PB affected the diurnal variation of hormones; the decrease in estradiol concentration between 8 a.m. and 8 p.m. was eliminated and the decrease in estriol concentration became more clear. PB did not significantly affect the serum levels of the other hormones investigated. As an enzyme-inducer PB may affect the fate of sex hormones.
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000187:drug effects*; D004958:Estradiol / Q000097:blood; D004964:Estriol / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D010634:Phenobarbital / Q000494:pharmacology*; D011247:Pregnancy / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood
chemical_list: D012739:Gonadal Steroid Hormones; D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D004964:Estriol; D006854:Hydrocortisone; D010634:Phenobarbital