Barbiturate: Encyclopedia - Barbiturate

Barbiturate

Barbiturates are drugs that act as central nervous system (CNS) depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia. Some are also used as anticonvulsants.

Barbiturates are derivatives of barbituric acid.

Barbiturate - Medical uses

Today barbiturates are infrequently used as anticonvulsants and for the induction of anesthesia. Benzodiazepines were made as barbiturate alternatives and as such are more widely used and prescribed today than the barbiturate drugs.

These barbiturates are available in the U.S.:

• Amobarbital (Sodium Amytal; hypnotics)
• Aprobarbital (hypnotic)
• Butabarbital (hypnotics)
• Butalbital (Fiorinal; sedative)
• Hexobarbital (Sombulex; hypnotic/anesthetic)
• Methylphenobarbital (Mebaral; antianxiety, anticonvulsant)
• Pentobarbital (Nembutal; hypnotic)
• Phenobarbital (Luminal; hypnotic, sedative, anticonvulsant)
• Secobarbital (Seconal; hypnotic)
• Sodium thiopental
• Talbutal (Lotusate; hypnotic)
• Thiobarbital (anesthetic)

Sometimes two or more barbiturates are combined in a single tablet or capsule; perhaps the most well-known of these combinations is Tuinal, which consists of amobarbital and secobarbital in equal proportions.

Barbiturate - Barbiturate abuse

Barbiturates were very popular in the first half of the 20th century. In moderate amounts, these drugs produce a state of intoxication that is remarkably similar to alcohol intoxication. Symptoms include slurred speech, loss of motor coordination, and impaired judgment. Depending on the dose, frequency, and duration of use, one can rapidly develop tolerance, physical dependence, and psychological dependence on barbiturates. With the development of tolerance, the margin of safety between the effective dose and the lethal dose becomes very narrow. That is, in order to obtain the same level of intoxication, the tolerant abuser may raise his or her dose to a level that may result in coma or death. Although many individuals have taken barbiturates therapeutically without harm, concern about the addiction potential (withdrawal symptoms can include tonic-clonic or grand mal seizures potentially leading to permanent disability or even death) of barbiturates and the ever-increasing number of fatalities associated with them led to the development of alternative medications, namely benzodiazepines. Today, fewer than 10 percent of all sedative/hypnotic prescriptions in the United States are for barbiturates.

Barbiturate - History

• Dec 4, 1863 Barbituric acid is discovered by German researcher Adolf von Baeyer. His discovery came on the day of St. Barbara, so he chose the name "barbiturate" as a combination of St. Barbara and "urea". Another possible explanation is that he named the substance after his girlfriend Barbara.
• 1903 Barbital, the first medicinal barbiturate, is synthesized from barbituric acid by German scientists Emil Hermann Fischer and Joseph von Mering. It was marketed under the trade name Veronal.
• 1912 Phenobarbital is introduced under the trade name Luminal as a sedative-hypnotic.
• 1950s - 1960s Reports increase about side effects and dependence related to barbiturates.
• 1970 Pentobarbital (II), secobarbital (II), amobarbital (II), butabarbital (III), phenobarbital (IV), and barbital (IV) are all scheduled with the passage of the U.S. Drug Abuse Regulation and Control Act of 1970.
• 1971 Convention on Psychotropic Substances is signed in Vienna. Designed to regulate amphetamines, barbiturates, and other synthetics, the treaty today regulates amobarbital (III), butalbital (III), cyclobarbital (III), pentobarbital (III), allobarbital (IV), methylphenobarbital (IV), phenobarbital (IV), secbutabarbital (IV), and vinylbital (IV) as scheduled substances.

Barbiturate - Other non-therapeutical use

Barbiturates in high doses are used for physician-assisted suicide (PAS), and, in combination with a muscle relaxant, for euthanasia and for capital punishment by lethal injection.

Barbiturate - Barbiturate Poisoning

Barbiturates are sedatives used for seizure disorders, induction of anesthesia, and management of increased intracranial pressure. Barbiturates enhance the inhibitory neurotransmitter gamma amino butyric acid GABA and are general depressants to nerve and muscle tissue. Mild to moderate barbiturate toxicity mimics alcohol intoxication. Severe acute barbiturate toxicity results in CNS problems, including lethargy and coma. Constricted pupils, confusion, hypotension, poor coordination, respiratory depression, and coma may be found on physical exams. Although a barbituarte serum level may be obtained, the clinical presentation predicts the seriousness of the overdose. Attention must be given to the ABC's - airway, breathing and circulation. Although a barbiturate serum level may be obtained, the clinical presentation predicts the seriousness of the overdose. Gastric Lavage and and multiple doses of activated charcoal may be used to decontaminate the GI system. IV fluids and forced diuresis and alkalinization should be used for long acting barbiturate intoxication. In severe cases, hemodialysis may be necessary. Early death are usually a result of shock or cardiopulmonary arrest. Later death are usually the result of pulmonary complications such a aspiration pneumonia or pulmonary edema.

Barbiturate - Trivia

• Marilyn Monroe died from an overdose of barbiturates, as did George Sanders, Jean Seberg and Pier Angeli (Judy from Rebel Without a Cause).
• Judy Garland (Dorothy from the Wizard of Oz) also died from (accidental) barbiturate overdose.
• Michael Rabin, one of the most prodigious violinists America has ever had, became dependent on barbiturates and his death was partially linked to abuse of this drug.
• Jimi Hendrix's death was a combination of barbiturate overdose and vomit inhalation.

Adapted from the Wikipedia article "Barbiturate", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki