Phenobarbital (Phenobarbital) Central nervous system agent Anticonvulsant Status epilepticus, Insomnia, sedation, seizures. (Adults) Daytime sedation: 30 to 120 mg daily in 2 or 3 divided doses. Seizures: 60 to 200 mg/day. (Children) 3 to 6 mg/kg/day. Category D Sedation, Depression of respiration, nausea, vomiting, headache, Bradycardia, exacerbation of Porphyria, respiratory Depression, Erythema Multiforme, Stevens-Johnson syndrome. Pregnancy Risk Categories defined: A: Studies in pregnant women failed to show a risk to the fetus in the first trimester - with no evidence of risk in the later trimesters. B: Animals studies indicate no adverse effect to the fetus, but there are no adequate, clinical studies in pregnant women. C: Animal studies have shown an adverse effect on the fetus, but there are no adequate, clinical studies in humans. Despite potential risks, the drug may be useful in pregnant women. D: There is evidence of risk to the human fetus, but the potential benefits of use in pregnant women may be acceptable, despite potential risks. X: Studies in animals or humans show fetal abnormalities, or adverse reaction reports indicate evidence of fetal risk. Warning: the risks involved clearly outweigh any potential benefit from using the drug in pregnant women, regardless of trimester. NR: Not rated (i.e., no information available at this time as to the potential risks or benefits).