Barbiturate drugs belong to a class of sedatives that function by suppressing brain activity. Examples of barbiturates include thiopental, which has a very short duration of action and is used for anesthesia induction, and phenobarbital, which has a long duration of action and is sometimes prescribed as an anticonvulsant for epilepsy treatment. While barbiturates were previously utilized as anti-anxiety and sleep medications, they have largely been replaced by benzodiazepines and other non-barbiturate drugs. Due to their addictive nature and widespread misuse for their sedating effects, barbiturates are now classified as controlled substances.
The sedative effects of barbiturate drugs occur through the mechanism of drug molecules blocking the transmission of excitatory chemical signals between nerve cells in the brain, thereby reducing the cells’ responsiveness. Additionally, barbiturates, particularly phenobarbital, decrease the sensitivity of brain cells to abnormal electrical activity.
Barbiturate drugs carry potential adverse effects that encompass excessive drowsiness, unsteady gait, and, in certain instances, restlessness or excitability. An overdose of barbiturates can have fatal consequences, particularly when combined with alcohol, as this dangerously enhances their depressant impact on the brain, including the suppression of the respiratory center.
If used for an extended period exceeding a few weeks, barbiturates are prone to induce drug dependence, and upon discontinuation of treatment, withdrawal symptoms such as insomnia and muscle twitching may manifest.