Thank you for your query.
I am surprised that the dose of the drug was not increased as your brother grew. He is very furtunate that he has not had any seizure
during this period. Now that he is more than 2 years seizure free the doctor should consider reducing the dose of the medicine and stopping it over the next few months instead of changing the medicine.
I hope I have answered your query to your satisfaction.
Wishing your brother all the best.
Rajiv K Khandelwal