Methohexital is an ultrashort-acting barbiturate widely used in dentistry because of its rapid onset, predictable effects, and short duration of action. It was marked under the name brevital sodium for the intravenous anaesthesia. It has also been commonly used to induce deep sedation. Like other barbiturates, methohexital exerts its effects through the gamma-aminobutyric acid (GABA) receptor complex. By binding to its own receptor on the complex, methohexital augments the inhibitory effect of GABA on neurons and additionally can exert a similar effect independent of GABA.

Butalbital, 5-allyl-5-isobutylbarbituric acid, is a barbiturate with an intermediate duration of action. The different combinations with butalbital is approved. One of them is fioricet with codeine (butalbital, ccetaminophen, caffeine, and codeine phosphate) which is indicated for the relief of the symptom complex of tension (or muscle contraction) headache. Evidence supporting the efficacy and safety of fioricet with codeine in the treatment of multiple recurrent headaches is unavailable. Butalbital is well absorbed from the gastrointestinal tract and is expected to distribute to most tissues in the body. This compound in general may appear in breast milk and readily cross the placental barrier. Monoamine oxidase (MAO) inhibitors may enhance the CNS effects. The mechanism of action for butalbital is proposed the following: this compound binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Sodium thiopental (also known as Sodium Pentothal, thiopental) was discovered in 1930s by investigators working for Abbott Laboratories. Thiopental sodium was used for the induction of general anesthesia and is used as an adjunct to provide hypnosis during balanced anesthesia with other anesthetic agents, including analgesics and muscle relaxants. Thiopental sodium was also used as an adjunct for control of convulsive disorders of various etiology, including those caused by local anesthetics. Finally, thiopental sodium had been used to reduce the intracranial pressure in patients with increased intracranial pressure, if controlled ventilation is provided. Nevertheless, these prescriptions of drug were discontinued. In addition, this drug was banned for use in US executions. Thiopental sodium acts through the CNS with particular activity in the mesencephalic reticular activating system. It was shown, that mechanism of action of sodium thiopental via GABAA receptor. Thiopental binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.