Factors influencing serum levels of carbamazepine and carbamazepine-10,11-epoxide in children
Carbamazepine-10,11-epoxide (CBZ-E), the principal metabolite of carbamazepine (CBZ), is reported to have antiepileptic and toxic effects similar to CBZ. Steady-state CBZ and CBZ-E levels (high performance liquid chromatography, HPLC assay) were reviewed in 225 outpatient children and young adults t...
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Published in | Epilepsy research Vol. 4; no. 1; pp. 72 - 80 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
01.07.1989
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Carbamazepine-10,11-epoxide (CBZ-E), the principal metabolite of carbamazepine (CBZ), is reported to have antiepileptic and toxic effects similar to CBZ. Steady-state CBZ and CBZ-E levels (high performance liquid chromatography, HPLC assay) were reviewed in 225 outpatient children and young adults taking CBZ with or without other antiepileptic drugs (AEDs). In patients on CBZ alone, mean serum concentration of CBZ was 7.9 ± 1.9 μg/ml and of CBZ-E was 1.5 ± 0.6 μg/ml. The
CBZ-E
CBZ
ratio was 19.6 ± 2.4%. Serum CBZ increased with increasing age and with CBZ dose. CBZ-E increased with increasing CBZ dose but was unaffected by age. The
CBZ-E
CBZ
ratio progressively declined with age. Co-medication with barbiturates or valproic acid significantly increased CBZ-E. Phenytoin showed a similar trend while ethosuximide caused the least change. Patients on CBZ and two or more other AEDs had highest CBZ-E levels and
CBZ-E
CBZ
ratio. CBZ and CBZ-E levels are variably affected by age, CBZ dose, and co-medication with other AEDs. When other AEDs are administered, careful monitoring is especially indicated in order to avoid toxicity. |
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ISSN: | 0920-1211 1872-6844 |
DOI: | 10.1016/0920-1211(89)90060-0 |