barbital

Barbital is a barbiturate, a synthetic derivative of barbituric acid. The compound most commonly associated with the name is barbital, marketed under the brand Veronal. Barbital was one of the earliest hypnotic agents and was introduced in the early 20th century, with widespread use for the treatment of insomnia and as a preoperative sedative in some settings.

Chemically, barbital is the long-acting member of the barbiturate class, with two ethyl groups at the 5-position of the barbiturate ring. Pharmacologically, barbital acts by enhancing the activity of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABA-A receptor, increasing chloride ion influx and producing sedation and hypnosis. It is relatively slow to onset and has a prolonged duration of action compared with shorter-acting barbiturates. It is primarily metabolized in the liver and excreted by the kidneys.

Clinically, barbital has largely fallen out of favor as a hypnotic due to safety concerns, including tolerance, dependence, withdrawal, and the risk of fatal respiratory depression when combined with other central nervous system depressants. It has a narrow therapeutic window and can interact with a wide range of medications and substances. Today, shorter-acting sedatives and non-barbiturate alternatives, such as benzodiazepines and nonbenzodiazepine sleep aids, are generally preferred. Barbital may still be encountered in historical reviews, older medical literature, or in regions where barbiturates are still available, but its use is much less common in modern practice.