Products
Pentobarbital is no longer commercially available as a finished drug for human use in many countries. Legally, it belongs to narcotics (schedule b) and is available only by prescription. Pharmacies can order the powder from specialized suppliers.
Structure and properties
Pentobarbital (C11H18N2O3, Mr = 226.3 g/mol) exists as a white crystalline powder or as colorless crystals. It is odorless with a slightly bitter taste. It is very slightly soluble in water. In contrast, the sodium salt pentobarbital sodium, which is most commonly used and otherwise has identical properties, is very slightly soluble in water. However, solutions have a short shelf life and should be used immediately. Pentobarbital is a racemate. Barbiturates are derivatives of barbituric acid.
Effects
Pentobarbital (ATC N05CA01) has sedative, sleep-inducing, anesthetic, and central depressant properties. At high doses, death occurs from respiratory and cardiac arrest. Pentobarbital is a GABAA receptor agonist. Its effects are due to an increase in the opening time of the chloride channel at the receptor, resulting in a reduction in neuronal excitability due to an increase in chloride conductance. Pentobarbital has a long half-life ranging from 15 to 50 hours.
Indications for use
Pentobarbital was previously used in human medicine as a sedative and sleep aid, among other uses. Because of its potential adverse effects and risk of poisoning, it is no longer commercially available. An overdose is life-threatening and pentobarbital was therefore often used for suicides. The most famous victim of a pentobarbital overdose is Marilyn Monroe, who died at age 36 from poisoning with Nembutal capsules and chloral hydrate. Euthanasia organizations use an aqueous solution of 15 g of sodium pentobarbital to induce the death of seriously ill people. An antinausea agent, such as metoclopramide, is administered beforehand. If swallowing is not possible, it can also be administered directly into the stomach by a tube. A solution can also be prepared with excipients to improve taste. See also under euthanasia medications.
