Hi,
Thanks for placing your query here.
I can appreciate your concerns.
Oxetol is the trade name & the actual medicine is oxcarbamazepine.
This is an effective anti epeptic drug & indeed the first choice in partial seizures (means the seizure activity starts from one part of brain & spreads outwards)
150 mg twice a day is initial dose & slowly will be increased.
Side effects include low blood sodium ,
allergic reaction, skin rashes,sleepiness,
dizziness,visual problems & 
stomach upset. 
Make sure the medicine is taken at fixed times each day & no dose is missed .
Missing a dose  of anti epileptic drugs is known to precipitate seizure.
Hope I have answered your query. 
If you have any further questions I will be happy to help. 
Wish her a good health.