Zarontin (ethosuximide) generally is used only for the brief staring spells known as absence seizures (formerly known as "petit mal" seizures). It is highly effective and safe for children who have the disorder known as childhood absence epilepsy. Zarontin is often the first choice of medication for children with this disorder.

Doctors have studied large numbers of patients to find out how well Zarontin controls absence seizures. In one early study, 95% of patients had the number of seizures reduced by at least half, and about half the patients had them reduced by at least 90%.

Some children who have absence seizures have more complicated disorders that are harder to treat and may not be outgrown. Zarontin also controls absence seizures in many of these children, but other seizure medicines often are needed to control other types of seizures.

Zarontin can be used in combination with other seizure medicines for patients who have other kinds of seizures in addition to absences. No single combination of seizure medicines is perfect for everyone. Sometimes, a series of combinations must be tried before finding what is best for the individual patient.