I think a lot of responses would have to based on what kind of epilepsy and what caused/causes it. My daughter is considered 'seizure prone' ( we don't use the epilepsy label too much due to this), but hers are considered to be the cause of her operations and such over the years. She has hydrocephalus on top of her birth defects, and they figure the seizures started because of all of her neurosurgical/craniofacial problems with her hydrocepalus. Complicated, huh?

However, until this year, most of her seizures were related to either head bumps, surgeries, and stress after surgeries. But, this year she's had about four major ones, and we can only figure (after testing everything) that it may just be teenage hormones kicking in. Unfortunately for her in November, she had a lot of congestion during one, and aspirated some of it during a seizure and caused pneumonia leaving her in the hospital for a week. (and now she may have scar tissue in her trachea because of the intubation that day).
I also have a coworker who has it and hers was caused by running headon into a glass door as a child.
I would personally recommend joining a listserv support group as soon as possible. Support groups can be a real great support during this time for you. We're part of one for our daughter's problems, and have learned so much, as well as sharing so much.

Good luck.
Kim
P.S. Tell your friend that Carbatrol will cause major weight gain, though! Yuck. Our daughter has put on so much weight because of it. Luckily we've finally gotten her off of it.