Paramethadione is an oxazolidinedione anticonvulsant used in the treatment of petit mal epilepsy, a condition generally requiring treatment only in childhood. It is chemically related to trimethadione, a drug that has largely been abandoned in the marketplace and is not used due to its severe effects on the human fetus. Paramethadione has only slightly less and similar developmental toxicity potential, and its clinical use have also been increasingly limited due to this toxicity in favor of less toxic anticonvulsants. In human subjects, it was established that paramethadione, like its congener, produces a syndrome of developmental toxicity termed “fetal trimethadione syndrome.” Paramethadione is a smaller hydrophilic compound capable of acting as a hydrogen bond acceptor. It is of average polarity in comparison to the other human developmental toxicants.