Chronic antiepileptic drug therapy: classification by medication regimen and incidence of decreases in serum thyroxine and free thyroxine index.
Results are described on the association of decreased serum total thyroxine (T4) and free thyroxine index (FTI) with antiepileptic drug therapy in a group of randomly selected chronically medicated outpatients (n = 291). For monotherapy subgroups (n = 164), the highest incidence (T4, 23.9%; FTI, 25.4%) of below normal values occurred in patients medicated with carbamazepine (CBZ), followed by phenytoin [(PHT) T4, 13.2%; FTI, 7.9%], and phenobarbital [(PB) (T4, 3.4%; FTI, 0%]. No T4 and FTI values below normal were detected in any patients (n = 30) on chronic valproic acid (VPA) monotherapy. For CBZ monotherapy (n = 67), women (n = 37) had a higher frequency of below normal values of T4 (p less than 0.05) and FTI (p less than 0.001) than men (n = 30). Therefore, the order of decreasing T4 and FTI effect was as follows: CBZ (women) greater than CBZ (men) greater than PHT greater than PB greater than VPA. For polytherapy subgroups (n = 127), the highest incidence (T4, 51.9%; FTI, 48.1%) was found in patients medicated with PHT and CBZ, followed by PHT and VPA (T4, 37.0%; FTI, 23.9%), and PHT and PB (T4, 17.2%; FTI, 10.3%). For PHT and CBZ poly-therapy (n = 52), women (n = 21) had a higher frequency of below normal values of T4 (p less than 0.05) and FTI (p less than 0.001) than men (n = 31). The magnitude of the decreasing T4 and FTI effect was greater for polytherapy subgroups (versus monotherapy subgroups) and in order as follows: PHT + CBZ (women) greater than PHT + CB (men) greater than PHT + VPA greater than PHT + PB.(ABSTRACT TRUNCATED AT 250 WORDS)
Haidukewych
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Epilepsy Center of Michigan, Detroit 48201.
Rodin
E A
EA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D013974:Thyroxine / Q000097:blood*
D000927:Anticonvulsants; D013974:Thyroxine