Carbamazepine and falsely positive screening tests for Cushing's syndrome.
A case of markedly elevated 24-hour urine-free cortisol levels, mainly due to interference with carbamazepine when measuring with high performance liquid chromatography but also due to increased fluid intake, is presented. Moreover, the 1 mg overnight dexamethasone suppression test was positive and the midnight serum cortisol level was slightly increased, probably as a result of carbamazepine-induced activity of CYP3A4 and increased levels of cortisol binding globulin.
Tiong
Keith
K
Falhammar
Henrik
H
D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology*; D002220:Carbamazepine / Q000494:pharmacology*; D002940:Circadian Rhythm; D003480:Cushing Syndrome / Q000175:diagnosis*; D003907:Dexamethasone; D017029:Epilepsy, Complex Partial / Q000188:drug therapy; D005189:False Positive Reactions; D005260:Female; D006628:Hirsutism / Q000209:etiology; D006801:Humans; D006854:Hydrocortisone / Q000652:urine*; D011141:Polyuria / Q000209:etiology
D000927:Anticonvulsants; D002220:Carbamazepine; D003907:Dexamethasone; D006854:Hydrocortisone