Paraldehyde is a sedative and anti-convulsant. Rarely used today (and no longer produced in the United States) it was first used clinically in 1886. It was formerly the first line treatment for delirium tremens, but has been replaced by other drugs. It can be used to treat seizures as, unlike benzodiazepines, it does not depress breathing.
As paraldehyde reacts with plastic, rubber and oxygen, it must be stored in sealed glass ampules. However, it can be administered orally (usually with something to hide the taste, like milk) or rectally. Intravenous use is rather more rare as it can react with a syringe if not used quickly..