BACKGROUND: Thyrotropin-releasing hormone is an endogenous tripeptide with endocrine-independent neurophysiologic properties that may be relevant to affective or seizure disorders. We studied the effect of carbamazepine, which has both mood-stabilizing and anticonvulsant properties, on cerebrospinal fluid thyrotropin-releasing hormone levels in affectively ill patients. METHOD: Paired cerebrospinal fluid samples were collected from nine inpatients with mood disorders, both while medication free and while taking carbamazepine for an average of longer than 1 month at 950 mg/d, achieving blood levels of 8.8 mg/L. RESULTS: Carbamazepine treatment was consistently and significantly associated with increased cerebrospinal fluid thyrotropin-releasing hormone levels (P < .0001). CONCLUSION: As carbamazepine-induced increases in thyrotropin-releasing hormone levels could be relevant to either its psychotropic or anticonvulsant properties, further clinical and preclinical investigation of this finding appears indicated.
BACKGROUND:Thyrotropin-releasing hormone is an endogenous tripeptide with endocrine-independent neurophysiologic properties that may be relevant to affective or seizure disorders. We studied the effect of carbamazepine, which has both mood-stabilizing and anticonvulsant properties, on cerebrospinal fluid thyrotropin-releasing hormone levels in affectively ill patients. METHOD: Paired cerebrospinal fluid samples were collected from nine inpatients with mood disorders, both while medication free and while taking carbamazepine for an average of longer than 1 month at 950 mg/d, achieving blood levels of 8.8 mg/L. RESULTS:Carbamazepine treatment was consistently and significantly associated with increased cerebrospinal fluid thyrotropin-releasing hormone levels (P < .0001). CONCLUSION: As carbamazepine-induced increases in thyrotropin-releasing hormone levels could be relevant to either its psychotropic or anticonvulsant properties, further clinical and preclinical investigation of this finding appears indicated.