|Systematic (IUPAC) name|
|Pregnancy cat.||D (USA)|
|Legal status||UN:Schedule IIIUSA: Schedule II (oral and parenteral); Schedule III (rectal), UK: Class B Controlled Substance|
|Routes||Oral, Intravenous, Intramuscular, Rectal; also Intraperitoneal & Intracardiac (for animal euthanasia)|
|Bioavailability||70-90% oral; 90% rectal|
|ATC code||N05 QN51|
| (what is this?)
Pentobarbital (US English) or pentobarbitone (UK English) is a short-acting barbiturate. Pentobarbital can occur as both a free acid and as a salts of elements such as sodium and calcium. The free acid is only slightly soluble in water and ethanol.
One brand name for this drug is Nembutal, coined by Dr. John S. Lundy, who started using it in 1930, from the structural formula of the sodium salt—Na (sodium) + ethyl + methyl + butyl + al (common suffix for barbiturates). Nembutal is trademarked and manufactured by the Danish pharmaceutical company Lundbeck, and is the only injectable form of pentobarbital approved for sale in the United States.
In high doses, pentobarbital causes death by respiratory arrest. In the United States, the drug has been used for executions of humans, but this usage is forbidden by the owner and manufacturer of the drug who, in accordance with Danish law and European human rights law, refuses to sell it to customers likely to use it for this purpose. It was banned in 1997 
Typical applications for pentobarbital are sedative, hypnotic for short term, preanesthetic and control of convulsions in emergencies.
It is also used as a veterinary anesthetic agent.
Pentobarbital also has an application in reducing intracranial pressure in Reye's syndrome, traumatic brain injury and induction of coma in cerebral ischemia patients. Pentobarbital-induced coma has been advocated in patients with acute liver failure refractory to mannitol.
Pentobarbital can induce death when used in high doses. It is used for euthanasia for humans as well as non-human animals.
In the Netherlands, the standard protocol for physician-assisted suicide is intravenously induced thiopental anesthesia, followed by bromide of alcuronium- or pancuronium-induced respiratory arrest. A concentrated oral solution of 100 ml containing 9 grams of pentobarbital sodium along with sugar syrup in a 20% ethanol solution is a standard solution used for self administration by patient.
The dosage of pentobarbital indicated for physician-assisted suicide in Oregon, US is typically 10 g in liquid form. This is considerably higher than the dose for the management of status epilepticus. 
Pentobarbital has been used or considered as a substitute for other drugs traditionally used in the United States for execution when they are in short supply. Such use however is illegal under Danish law, and when this was discovered, the owner of the drug, Lundbeck, stopped selling it to states that practice death penalty after public outcry in Danish media. US distributors of the drug are forbidden by the owner to sell it to any customers, such as several state authorities, that practice or participate in executions of humans.
Texas began using pentobarbital for executing death row inmates by lethal injection on July 18, 2012. The use of pentobarbital has been considered by several states, including Ohio, Arizona, Idaho and Washington; those states made the decision to switch following shortages of the pancuronium bromide, a muscle relaxant previously used as one component in a three-drug cocktail.[unreliable source?]
In October 2013, Missouri changed its protocols to allow for a compounded pentobarbital to be used in a lethal dose for executions. On November 20, 2013, Joseph Paul Franklin was executed by the state of Missouri. He was the first inmate executed in three years in the state and the first to die by a single dose of pentobarbital.
Pentobarbital is synthesized by methods analogous to that of amobarbital, the only difference being that the alkylation of α-ethylmalonic ester is carried out with 2-bromopentane (not 1-bromo-3-methylbutane) to give pentobarbital.
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