epilepsy
"I took Dilantin for over 20 years and always felt tired. I regularly had seizures 2-3 times a year while taking this medicine. My doctor took me off Dilantin and I transitioned to Levetiracetam (Keppra) because long term use of Dilantin can promote osteoporosis. I have been seizure free ever since and experience no side effects. I also feel more energy as a result of getting off Dilantin."