Drugs & Medication

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 believed to be GABA (gamma-aminobutyric acid) agonists, acting on the GABA-A receptor. GABA is the principal inhibitory neurotransmitter in the mammalian CNS.

Barbiturates are derivatives of barbituric acid.

Contents 1 Medical uses 2 Recreational use 3 Other non-therapeutical use 4 History 5 Poisoning 6 Famous users 7 References

Medical uses

Today barbiturates are infrequently used as anticonvulsants and for the induction of anesthesia. Benzodiazepines were made as safer barbiturate alternatives as they are virtually impossible to overdose and thus help thwart individuals with suicidal tendencies. Since the introduction of Diazepam in 1963, the first benzodiazepine prescibed for clinical use, barbiturates have been gradually phased out from use. Some of the barbiturates available are:

• 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.

Recreational use

Barbiturates were very popular in the first half of the twentieth 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.

Other non-therapeutical use

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

History

• Dec 4, 1863 Barbituric acid is discovered by German researcher Adolf von Baeyer. His discovery came on the day of St. Barbara, the patron saint of chemistry, 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.

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 barbiturate 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. Gastric Lavage 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 deaths are usually a result of shock or cardiopulmonary arrest. Later deaths are usually the result of pulmonary complications such as aspiration pneumonia or pulmonary edema.

Famous users

• Ryunosuke Akutagawa - the renowned Japanese writer who wrote Rashomon , committed suicide by overdosing on barbiturates on July 24, 1927.
  Judy Garland died from an accidental barbiturate overdose
  Marilyn Monroe also died from an overdose of barbiturates, as did George Sanders, Kenneth Williams (although an open verdict was recorded) and Jean Seberg.
  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 these drugs.
  Jimi Hendrix's death was a combination of barbiturate overdose and vomit inhalation.
  Edie Sedgwick died in 1971 of barbiturate overdose. Death was said to be accidental/suicidal.
  Tim Buckley, singer-songwriter and father of Jeff Buckley, died from an accidental overdose of heroin, alcohol, and barbiturates.
  Ruan Lingyu committed suicide by overdosing on barbiturates on March 8, 1935.
  Johnny Cash abused barbiturates during the height of his career.
  Elvis Presley used barbiturates in the last years of his life, but whether this contributed to his death is disputed.
  Margaux Hemingway died from an overdose of phenobarbital.
  Dorothy Kilgallen died in 1965 of an alcohol and seconal overdose. It is unclear whether the overdose was accidental or murder.
  Diane Arbus committed suicide in 1971 by taking barbiturates and slitting open her wrists.

References

• U.S. Drug Enforcement Agency Source for some public domain text used on this page.
• Erowid.org - Barbiturates
• Barbiturate chemistry