Thanks for using Healthcaremagic,
Your husband had seizures and now on anticonvulsant therapy, Levetiracetam
sodium the symptoms you have described may be due to effect of these drugs it is common to have drowsiness
after taking these drugs.
This possible if he did not sleep yesterday then he is feeling heaviness in head.
He should take rest and then see if it helps.
If anything abnormal like headache or irritability or unsteady gait
or coordination problem then you should report it to treating Physician to see if any dose adjustment is required.
He should take his medicines regularly at proper time to have full effect.
Hope this helps.
Wish him good health.
Dr.Akhilesh Dubey M.D.