Phenobarbital (INN) is a long-acting barbiturate and the most widely used anticonvulsant worldwide, and the oldest still commonly used. It also has sedative and hypnotic properties, but as with other barbiturates, it has been superseded by the benzodiazepines for these indications. The World Health Organization recommends its use as first-line for partial and generalized tonic–clonic seizures (those formerly known as grand mal) in developing countries. It is a core medicine in the WHO Model List of Essential Medicines, which is a list of minimum medical needs for a basic health care system. In more affluent countries, it is no longer recommended as a first- or second-line choice anticonvulsant for most seizure types, though it is still commonly used to treat neonatal seizures.