Phenobarbital is useful in treating many kinds of seizures in children. It is often considered the first choice to treat certain seizures in newborn infants.

Phenobarbital also has been widely used to prevent seizures that sometimes accompany a high fever in infants or young children. It does not enter the body quickly enough to prevent these seizures if it is only given after the fever starts, however, so the child must take it every day. Seizures of this kind usually cause no lasting harm, so most children should not be given phenobarbital to prevent them.

Phenobarbital has a reputation for causing problems with behavior or learning in children. Reports from various studies have not always agreed, perhaps because individual children are affected in different ways. The problems are probably not as serious for most children as many doctors think they are, but other seizure medicines may be preferred as a first choice for long-term use in children.

Side effects are much more likely to be troublesome if high doses are given or if too high a dose is given to start. It may be necessary to increase the dosage very slowly over several months. The doctor will calculate the dosage for a child based on the child's weight.

Reviewed February 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.