The medicine in Encorate
Chrono is Sodium Valporate, which is mainly used for the condition of seizure
. Although this medicine is not addicting, but continous used without any prescription is always wrong.
It is important to know first that your bother is having any type of condition for which he was prescribed this medicaiton or he himself start this without any consultaltion. If he is taking this medication after some consultation for some conditon, than I would advise you to conslut the same doctor and give him the details of the problem which your brother is right now facing because of overdosing and he may require something to stop this type of impusive behaviour.
And if he is taking this medication without any consulation and just for fun than you can stop this medication and consult and try to find out if he is having some problem or some addicting nature, that may require treatment.
Thanks and take care