Suggest Treatment For Absence Seizures

My son is 34 and has seizures due to a tba.He takes depakote er and keppra. His seizures are controlled..but he recently started smoking and since he has had several absence seizures. He use to dip skoal and i noticed when he would have a dip in his mouth he would have a absence seizure and start to choke. Does the tobacco product cause the seizures?