Pentobarbital is a short-acting barbiturate

Barbiturate

Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, as hypnotics, and as anticonvulsants...

 that was first synthesized in 1928. Pentobarbital is available as both a free acid and a sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 salt, the former of which is only slightly soluble in water and ethanol

Ethanol

Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

.
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

Ethyl group

In chemistry, an ethyl group is an alkyl substituent derived from ethane . It has the formula -C2H5 and is very often abbreviated -Et.Ethylation is the formation of a compound by introduction of the ethyl functional group, C2H5....

 + methyl + butyl

Butyl

In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula -C4H9, derived from either of the two isomers of butane....

 + al (common suffix for barbiturates).

Approved

Pentobarbital's FDA

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

-approved human uses include treatment of seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

s and preoperative (and other) sedation

Sedation

Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure...

; it is also approved as a short-term hypnotic

Hypnotic

Hypnotic drugs are a class of psychoactives whose primary function is to induce sleep and to be used in the treatment of insomnia and in surgical anesthesia...

.

Unapproved / investigational / off-label

Off-label uses of pentobarbital include reduction of intracranial pressure in Reye's syndrome

Reye's syndrome

Reye's syndrome is a potentially fatal disease that causes numerous detrimental effects to many organs, especially the brain and liver, as well as causing a lower than usual level of blood sugar . The classic features are liver damage, aspirin use and a viral infection...

, traumatic brain injury and induction of coma in cerebral ischemia

Cerebral ischemia

Brain ischemia, also known as cerebral ischemia, is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus to the death of brain tissue or cerebral infarction / ischemic stroke...

 patients. Pentobarbital-induced coma has been advocated in patients with acute liver failure refractory to mannitol

Mannitol

Mannitol is a white, crystalline organic compound with the formula . This polyol is used as an osmotic diuretic agent and a weak renal vasodilator...

.

Veterinary medicine

In veterinary medicine

Veterinary medicine

Veterinary Medicine is the branch of science that deals with the prevention, diagnosis and treatment of disease, disorder and injury in non-human animals...

, sodium pentobarbital is used as an anaesthetic.
It is also used by itself, or in combination with complementary agents such as phenytoin

Phenytoin

Phenytoin sodium is a commonly used antiepileptic. Phenytoin acts to suppress the abnormal brain activity seen in seizure by reducing electrical conductance among brain cells by stabilizing the inactive state of voltage-gated sodium channels...

, in commercial animal euthanasia

Animal euthanasia

Animal euthanasia is the act of putting to death painlessly or allowing to die, as by withholding extreme medical measures, an animal suffering from an incurable, especially a painful, disease or condition. Euthanasia methods are designed to cause minimal pain and distress...

 injectable solutions.

Human euthanasia

Pentobarbital has also been used for physician-assisted suicide.
In the US

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 state of Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 "oral doses of a barbiturate" have been used for this purpose.

Also in Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

and the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

. It was also used in the Northern Territory

Northern Territory

The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...

 of Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, prior to euthanasia becoming illegal in that region.

Capital punishment

Pentobarbital has been approved or considered for use in executions

Capital punishment

Capital punishment, the death penalty, or execution is the sentence of death upon a person by the state as a punishment for an offence. Crimes that can result in a death penalty are known as capital crimes or capital offences. The term capital originates from the Latin capitalis, literally...

 in various U.S. states.

The Danish manufacturer of pentobarbital, Lundbeck

Lundbeck

H. Lundbeck A/S is a Danish international pharmaceutical company engaged in the research and development, production, marketing, and sale of drugs for the treatment of disorders in the central nervous system , including depression, schizophrenia, Alzheimer’s disease, Parkinson’s disease,...

, expressed displeasure at this use of their product, and on July 1, 2011, announced they would block sales of the drug to U.S. prisons that carry out the death penalty.

Lundbeck is dedicated to saving people’s lives. Use of our products to end lives contradicts everything we are in business to do. Lundbeck is opposed to the use of its product for the purpose of capital punishment.

They explained this decision with their commitment to UN human rights principles.

Metabolism

Pentobarbital undergoes first-pass metabolism

First pass effect

The first-pass effect is a phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation. It is the fraction of lost drug during the process of absorption which is generally related to the liver and gut wall...

 in the liver and possibly the intestines.

Drug interactions

Administration of alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

, opioid

Opioid

An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...

s, antihistamine

Antihistamine

An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...

s, other sedative-hypnotic

Sedative

A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....

s, and other central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 depressants will cause possible additive effects.

Chemistry

Pentobarbital is synthesized by methods analogous to that of amobarbital

Amobarbital

Amobarbital is a drug that is a barbiturate derivative. It has sedative-hypnotic and analgesic properties. It is a white crystalline powder with no odor and a slightly bitter taste. It was first synthesized in Germany in 1923...

, 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.

External links

• Barbiturates on Erowid
  Erowid
  Erowid, also called The Vaults of Erowid, is an online library of information about psychoactive plants and chemicals and other topics on altered states of consciousness such as meditation and lucid dreaming. It provides information about legal and illegal substances, including their desired and...