Seizure issue despite taking medicine.

My grandfather's age is 84 and he has been taking oxcarbazepine 300 mg tablet(oxcarbazepine colour yellow fcp and titanium dioxide ip) but still today his condition worsened when he was taking tea and he experienced another seizure for 2-3 mintues. He is already a brain patient from 1992 (at that time he had a brain stroke and due to no medical advancement he doesn't get a treatment at that time) but in 2012 he started getting seizures and he had operated for hernia in 2022 and still getting medicine for urine and his epilepsy medicines brand recently changed by pharmacist due to unavailability in area...please suggest what should we do now to keep him healthy and he was also having mild breathing issue yesterday