Phenytoin has been used for over 50 years. Thus, the characteristics and side-effects have been well elucidated. Its primary use is for treatment of partial epilepsy, including simple and complex partial seizures, as well as generalized tonic-clonic seizures, whether of primary or partial onset.
Felbamate is a broad-spectrum anti-epileptic drug. It is not considered to be a first-line drug because of its potential for serious idiosyncratic side-effects, including potentially fatal aplastic anaemia (incidence of 1 in 3000) and hepatic failure (incidence of 1 in 10000).