I'v Only Had One Known Seizure Approx. 1/1/2 Months Ago.

I'v only had one known seizure approx. 1/1/2 months ago. That occurred several days after two brain surgeries.I was prescribed 300mg Dilantin per day. I'm concerned about the long term side effects this drug will have on my over all health. Should I asked my doctor to take me off this drug since there has been no sign of any seizures since.