phenobarbital /fē′nəbär′bital/ , a barbiturate anticonvulsant and sedative-hypnotic. Also called sodium phenobarbital. ▪ INDICATIONS: It is prescribed in the treatment of seizure disorders and as a long-acting sedative. ▪ CONTRAINDICATIONS: Porphyria, severe pain, respiratory problems, or known hypersensitivity to this drug or other barbiturates prohibits its use. ▪ ADVERSE EFFECTS: Among the most serious adverse reactions are ataxia, porphyria, paradoxic excitement, drowsiness, occasional rashes, and, rarely, blood dyscrasias. It is involved in many drug interactions.
