It is often mistaken for "truth serum", or sodium amytal, an intermediate-acting barbiturate that is used for sedation and to treat insomnia, but was also used in so-called sodium amytal "interviews" where the person being questioned would be much more likely to provide the truth whilst under the influence of this drug. When dissolved in water, sodium amytal can be swallowed, or it can be administered by intravenous injection. The drug does not itself force people to tell the truth, but is thought to decrease inhibitions and slow creative thinking, making subjects more likely to be caught off guard when questioned, and increasing the possibility of the subject revealing information through emotional outbursts. Lying is somewhat more complex than telling the truth, especially under the influence of a sedative-hypnotic drug.The memory-impairing effects and cognitive impairments induced by sodium thiopental are thought to reduce a subjects ability to invent and remember lies. This practice is no longer considered legally admissible in court, owing to findings that subjects undergoing such interrogations may form false memories, putting the reliability of all information obtained through such methods into question. Nonetheless, it is still employed in certain circumstances by defense and law enforcement agencies as a "humane" alternative to torture interrogation when the subject is believed to have information critical to the security of the state or agency employing the tactic. Chemistry
In 1988, the synthesis and binding studies of an artificial receptor binding barbiturates by six complementary hydrogen bonds was published.
Since this first article, different kind of receptors were designed, as well as different barbiturates and cyanurates, not for their efficiencies as drugs but for applications in supramolecular chemistry, in the conception of materials and molecular devices. The preferred IUPAC name of the base compound, barbituric acid, is  1,3-diazinane-2,4,6-trione. Different barbiturates has different substituents in the basic structure, mainly in position 5 on the ring.Sodium barbital and barbital have also been used as pH buffers for biological research, e.g., in immuno-electrophoresis or in fixative solutions. Classification
Barbiturates are classified based on the duration of action. Examples of each class include:
Ultra short acting (30 minutes): thiopentone, methohexitone
Short acting (2 hours): hexobarbitone, cyclobarbitone, pentobarbitone, secobarbitone
Intermediate acting(3–6 hours): amobarbitone, butabarbitone
Long acting (6 hours): phenobarbitone

Indications
Indications for the use of barbiturates include:
Seizure
Neonatal withdrawal syndrome
Insomnia
Anxiety
Inducing anesthesia

Side effects
There are special risks to consider for older adults, and women who are pregnant. When a person ages, the body becomes less able to rid itself of barbiturates. As a result, people over the age of sixty-five are at higher risk of experiencing the harmful effects of barbiturates, including drug dependence and accidental overdose. When barbiturates are taken during pregnancy, the drug passes through the placenta to the fetus. After the baby is born, it may experience withdrawal symptoms and have trouble breathing. In addition, nursing mothers who take barbiturates may transmit the drug to their babies through breast milk. A rare adverse reaction to barbiturates is Stevens–Johnson syndrome, which primarily affects the mucous membranes.