This Cys-loop receptor superfamily of ion channels includes the neuronal nACh receptor channel, the 5-HT3 receptor channel, and the glycine receptor channel. However, while GABAA receptor currents are increased by barbiturates (and other general anesthetics), ligand-gated ion channels that are predominantly permeable for cationic ions are blocked by these compounds. For example, neuronal nAChR channels are blocked by clinically relevant anesthetic concentrations of both thiopental and pentobarbital. Such findings implicate (non-GABA-ergic) ligand-gated ion channels, e.g. the neuronal nAChR channel, in mediating some of the (side) effects of barbiturates. This is the mechanism responsible for the (mild to moderate) anesthetic effect of barbiturates in high doses when used in anesthetic concentration. Interactions
Drug interactions with barbiturates are:

alcohol
alprazolam
anticoagulants
antihistamines
atazanavir
birth-control pills
boceprevir
clonazepam

Caution
Medications such as opioids, Benzodiazepines
alcohol
asthma
kidney or liver problems
Heart disease
Substance use disorder
Depression
History of suicidal thoughts

History
Barbituric acid was first synthesized 27 November 1864, by German chemist Adolf von Baeyer. This was done by condensing urea with diethyl malonate. There are several stories about how the substance got its name. The most likely story is that Baeyer and his colleagues went to celebrate their discovery in a tavern where the towns artillery garrison were also celebrating the feast of Saint Barbara – the patron saint of artillerymen. An artillery officer is said to have christened the new substance by amalgamating Barbara with urea. Another story was barbiturate was invented on the feast day of St. Barbara. Another story holds that Baeyer synthesized the substance from the collected urine of a Munich waitress named Barbara.
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.