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

Barbiturates are derivatives of barbituric acid.

Medical uses

Today barbiturates are mainly used as anticonvulsants and for the induction of anesthesia.

These barbiturates are available in the U.S.:

• Amobarbital (Sodium Amytal; hypnotic)
• Aprobarbital (hypnotic)
• Butabarbital (hypnotic)
• Butalbital (Fiorinal; sedative)
• Hexobarbital (Sombulex; hypnotic/anesthetic)
• Mephobarbital (antianxiety)
• 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 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 to 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, less 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), and, in combination with a muscle relaxant, for euthanasia and for capital punishment by lethal injection.

References

• Text partially derived from public domain text from U.S. Drug Enforcement Agency (http://www.usdoj.gov/dea/concern/depressants.html).