Phenobarbital is a barbiturate used therapeutically as a hypnotic, sedative, and anticonvulsant in the management of generalized tonic-clonic (grand mal) and partial seizures. It shares the active chemical moiety with another anticonvulsant drug, primidone. Phenobarbital is obtained by prescription as Luminal® and Sulfoton® and by many other trade names. It has a pregnancy category of D, based on the package label that states “barbiturates can cause fetal damage when administered to a pregnant woman. In animal studies, phenobarbital has shown developmental toxicity in mice, rats, and rabbits by oral and parenteral routes of administration, those pertinent to the human condition. Mortality of phenobarbital-exposed fetuses or infants was not reported to be a significant feature of the developmental toxicity profile of phenobarbital. Phenobarbital is average in size. It is hydrophobic and can participate as a hydrogen bond donor and acceptor. Phenobarbital is of average polarity in comparison to the other human developmental toxicants.