PHENSUXIMIDE & METHSUXIMIDE
(no longer readily available) and methsuximide are phenylsuccinimides that were
developed and marketed before ethosuximide. They are used primarily as
anti-absence drugs. Methsuximide is generally considered more toxic, and
phensuxim-ide less effective, than ethosuximide. Unlike ethosuximide, these two
compounds have some activity against maximal electroshock seizures, and
methsuximide has been used for partial seizures by some investigators.