title: The effective evaluation of thyroid status in patients on phenytoin, carbamazepine or sodium valproate attending an epilepsy clinic.
abstract: To assess the most efficient means of monitoring thyroid status in an epilepsy clinic, total thyroxine (T4), free thyroxine stimulating hormone (TSH) were measured in 71 adult patients treated long-term with either phenytoin (DPH), carbamazepine (CBZ) or sodium valproate (VAL). Twenty-seven patients with one or more abnormal thyroid hormone results were further investigated by a thyrotrophin releasing hormone (TRH) test and clinical assessment. T4 was found to be normal in 85% on VAL, 40% on CBZ and 39% on DPH. FT4 was normal in more patients, namely 95% on VAL, 70% on CBZ and 65% on DPH. The TRH tests indicated that FT4 was the most efficient screening test for hypothyroidism in this epileptic population. We estimate that the use of FT4 alone as a screening test would have reduced by 60% the number of TRH tests required.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000627:therapeutic use*; D002220:Carbamazepine / Q000627:therapeutic use; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000627:therapeutic use; D013972:Thyrotropin / Q000097:blood*; D013973:Thyrotropin-Releasing Hormone; D013974:Thyroxine / Q000097:blood*; D014635:Valproic Acid / Q000627:therapeutic use
chemical_list: D000927:Anticonvulsants; D002220:Carbamazepine; D013973:Thyrotropin-Releasing Hormone; D014635:Valproic Acid; D010672:Phenytoin; D013972:Thyrotropin; D013974:Thyroxine