Sodium 
valproate has increased the 
serum levels of 
ethosuximide by about 50%. Sedation occurred and 
ethosuximide dose reductions were necessary. However, other studies have described no changes or even reduced 
ethosuximide levels when 
valproate was also given. 
Ethosuximide may also lower 
valproate serum levels. 
 Monitor the effects of concurrent use, adjusting the 
ethosuximide dose and increasing the 
valproate dose accordingly. 
Valproate levels may be helpful.