<prompt> Answer this question truthfullyWhat is the explanation or definition for anticonvulsant drugs?  <response>: <reason> In the following list, the dates in parentheses are the earliest approved use of the drug.Main article: AldehydesParaldehyde 1882. One of the earliest anticonvulsants. Still used to treat status epilepticus, particularly where there are no resuscitation facilities.Stiripentol 2001 - limited availability. Indicated for the treatment of severe myoclonic epilepsy in infancy SMEI.Main article: BarbituratesBarbiturates are drugs that act as central nervous system CNS depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia. The following are classified as anticonvulsants:Phenobarbital 1912. See also the related drug primidone. Methylphenobarbital 1935. Known as mephobarbital in the US. No longer marketed in the UK Metharbital 1952. No longer marketed in the UK or US. Barbexaclone 1982. Only available in some European countries.Phenobarbital was the main anticonvulsant from 1912 till the development of phenytoin in 1938. Today, phenobarbital is rarely used to treat epilepsy in new patients since there are other effective drugs that are less sedating. Phenobarbital sodium injection can be used to stop acute convulsions or status epilepticus, but a benzodiazepine such as lorazepam, diazepam or midazolam is usually tried first. Other barbiturates only have an anticonvulsant effect at anaesthetic doses.Main article: BenzodiazepinesThe benzodiazepines are a class of drugs with hypnotic, anxiolytic, anticonvulsive, amnestic and muscle relaxant properties. The relative strength of each of these properties in any given benzodiazepine varies greatly and influences the indications for which it is prescribed. Long-term use can be problematic due to the development of tolerance and dependency. Of the many drugs in this class, only a few are used to treat epilepsy:Clobazam 1979. Notably used on a short-term basis around menstruation in women with catamenial epilepsy. Clonazepam 1974. Clorazepate 1972.The following benzodiazepines are used to treat status epilepticus:Diazepam 1963. Can be given rectally by trained care-givers. Midazolam NA. Increasingly being used as an alternative to diazepam. This water-soluble drug is squirted into the side of the mouth but not swallowed. It is rapidly absorbed by the buccal mucosa. Lorazepam 1972. Given by injection in hospital.Nitrazepam, temazepam, and especially nimetazepam are powerful anticonvulsant agents, however their use is rare do to an increased incidence of side effects and strong sedative and motor-impairing properties.Main article: BromidesPotassium bromide 1857. The earliest effective treatment for epilepsy. There would not be a better drug for epilepsy until phenobarbital in 1912. It is still used as an anticonvulsant for dogs and cats.Main article: CarbamatesFelbamate 1993. This effective anticonvulsant has had its usage severely restricted due to rare but life-threatening side effects.Main article: CarboxamidesThe following are carboxamides:Carbamazepine 1963. A popular anticonvulsant that is available in generic formulations. Oxcarbazepine 1990. A derivative of carbamazepine that has similar efficacy but is better tolerated.Main article: Fatty acidsThe following are fatty-acids:The valproates valproic acid, sodium valproate, and divalproex sodium 1967. Vigabatrin 1989. Progabide Tiagabine 1996.Vigabatrin and progabide are also analogs of GABA.Main article: FructoseTopiramate 1995.Gabapentin 1993. Pregabalin 2004.Main article: HydantoinsThe following are hydantoins:Ethotoin 1957. Phenytoin 1938. Mephenytoin Fosphenytoin 1996.Main article: OxazolidinedionesThe following are oxazolidinediones:Paramethadione Trimethadione 1946. EthadioneMain article: PropionatesBeclamideMain article: PyrimidinedionesPrimidone 1952.Main article: PyrrolidinesBrivaracetam Levetiracetam 1999. SeletracetamMain article: SuccinimidesThe following are succinimides:Ethosuximide 1955. Phensuximide MesuximideMain article: SulfonamidesAcetazolamide 1953. Sulthiame Methazolamide Zonisamide 2000.Main article: TriazinesLamotrigine 1990.Main article: UreasPheneturide PhenacemideMain article: AmidesValpromide Valnoctamide 