epilepsy
"I've been taking this medicine for years.  I was having difficulties keeping my medicine levels in the proper zone.  The extended release has been great.  I'm in a small group of people who need their Dilantin level slightly above the 10-20 range.  I'm able to stay at 20-22 with the proper dosages that have been prescribed for me.  I cannot take the generic brand. When I was on the generic, my levels were not as stable."