Pentobarbital

Pentobarbital

Clinical data
Pregnancy category	D (USA)
Routes of administration	Oral, Intravenous, Intramuscular, Rectal; also Intraperitoneal & Intracardiac (for animal euthanasia)
ATC code	N05CA01 (WHO)
Legal status
Legal status	USA: Schedule II (oral and parenteral); Schedule III (rectal)
Pharmacokinetic data
Bioavailability	70-90% oral; 90% rectal
Protein binding	20-45%
Metabolism	Hepatic
Elimination half-life	15-48 hours
Excretion	Renal
Identifiers
IUPAC name 5-Ethyl-5-(1-methylbutyl)- 2,4,6(1H,3H,5H)-pyrimidinetrione
CAS Number	76-74-4
PubChem CID	4737
DrugBank	APRD01174
E number	{{#property:P628}}
ECHA InfoCard	{{#property:P2566}}
Chemical and physical data
Formula	C11H18N2O3
Molar mass	226.1317

Pentobarbital is a short acting barbiturate that is available as both a free acid and a sodium salt, the former of which is only slightly soluble in water and ethanol. One trade 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).

Uses

Approved

Pentobarbital's FDA approved human uses include treatment of seizures and preoperative (and other) sedation; it is also approved as a short-term hypnotic.

In France, it is used in the treatment of insomnia, and as a preanesthetic.

Unapproved/Investigational/Off-Label

Off-label uses of pentobarbital include reduction of intracranial pressure in Reye's syndrome, traumatic brain injury and induction of coma in cerebral ischemia patients.

Veterinary medicine

In veterinary medicine sodium pentobarbital—traded under names such as Sagatal—is used as an anaesthetic. Pentobarbital is an ingredient in Equithesin.

Veterinary Euthanasia

It is used by itself, or more often in combination with complementary agents such as phenytoin, in commercial animal euthanasia injectable solutions. Trade names include Euthasol, Euthatal, Beuthanasia-D and Fatal Plus.

Human Euthanasia

Pentobarbital has also been used for physician-assisted suicide. Pentobarbital was used for this purpose in the Northern Territory of Australia, prior to euthanasia becoming illegal. It is also commonly used in Oregon for physician assisted suicide.

Folklore

A pentobarbital suppository was cited in an October 2006 news article in WorldNetDaily.com as the cause of death of Marilyn Monroe.

The Beatles were accusedfact|date=July 2007 of writing their 1966 hit Yellow Submarine while under the psychoactive effects of Nembutal, though band members denied the allegations.

The Clash makes a reference to it in the song The Right Profile from the album London Calling in which the lyrics read "Nembutal numbs it all, But I prefer… alcohol!".

Metabolism

Pentobarbital undergoes first-pass metabolism in the liver and possibly the intestines.

Drug Interactions

Administration of alcohol, opioids, antihistamines, other sedative-hypnotics, and other central nervous system depressants will additively increase the sedation caused by pentobarbital.

Tricyclic antidepressants decrease serum levels of pentobarbital.