Lack of pharmacokinetic interaction of levetiracetam on carbamazepine, valproic acid, topiramate, and lamotrigine in children with epilepsy.
OBJECTIVE
To determine whether levetiracetam (LEV) affects plasma concentrations of carbamazepine, valproic acid, topiramate, and lamotrigine in children with epilepsy.


METHODS
The potential for interaction of LEV with other antiepileptic drugs (AEDs) was assessed using plasma drug levels obtained in a randomized placebo-controlled phase III trial of adjunctive LEV in children receiving one or two concomitant AEDs. Multiple plasma AED levels at baseline and during adjunctive treatment with LEV or placebo were compared by repeated measures analysis of covariance and mean concentration ratios (treatment/baseline) were estimated with their 90% confidence intervals (CI).


RESULTS
The study population included 187 children receiving any concomitant AED alone or in combination. The geometric mean concentrations at baseline and during LEV treatment were carbamazepine 8.4 microg/ml versus 8.1 microg/ml (coefficient of variation, CV = 30%; n = 35); valproic acid 83.8 versus 82.5 microg/ml (CV = 38%; n = 23); topiramate 7.3 versus 7.2 microg/ml (CV = 82%; n = 28); lamotrigine 8.2 versus 7.7 microg/ml (CV = 62%; n = 22). For each AED, the mean concentration ratios (LEV/baseline) and their 90% CIs showed that AED concentrations were unaffected by concomitant LEV administration. No differences were observed between LEV and placebo.


CONCLUSIONS
LEV does not affect plasma concentrations of carbamazepine, valproic acid, topiramate, or lamotrigine in children with epilepsy.
Otoul
Christian
C
UCB Pharma SA, Chemin du Foriest, Braine-l'Alleud, Belgium. Christian.Otoul@ucb-group.com
De Smedt
Heidi
H
Stockis
Armel
A
D000293:Adolescent; D000927:Anticonvulsants / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002220:Carbamazepine / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism*; D005260:Female; D005632:Fructose / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D000077213:Lamotrigine; D000077287:Levetiracetam; D008297:Male; D017063:Outcome Assessment, Health Care; D010889:Piracetam / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D010919:Placebos; D000077236:Topiramate; D014227:Triazines / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D014635:Valproic Acid / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use
D000927:Anticonvulsants; D010919:Placebos; D014227:Triazines; D000077236:Topiramate; D005632:Fructose; D002220:Carbamazepine; D000077287:Levetiracetam; D014635:Valproic Acid; D000077213:Lamotrigine; D010889:Piracetam