Onfi is a prescription drug used in the treatment of seizures resulting from Lenox-Gastaut syndrome. This condition occurs in children who are two years and above and it is referred to as childhood epilepsy. It works by decelerating the rate of the brain's functioning. This reduces the amount of seizures experienced. Onfi is a prescription drug used together with other medicines to help control seizures. Onfi is in a class of medications called benzodiazepines. Onfi acts on the central nervous system to give you a calming effect. Onfi works by improving the activities of a certain chemical (GABA) that is produced naturally by the body. Onfi is typically taken once every 24 hours, most often before going to bed. If you are taking Onfi in divided doses, take the largest dose before you sleep. Onfi does not treat seizures or reduce the frequency at which seizure attacks occur. If your condition does not improve, talk to your doctor.