n.
Any of a class of heterocyclic compounds based on the parent structure, uric acid, and used in medicine.
They depress the central nervous system , acting particularly on certain parts of the brain , though they tend to depress the functioning of all the body's tissues. Long-acting barbiturates (e.g., barbital and phenobarbital) are used to treat epilepsy . Intermediate ones (e.g., amobarbital) are used to treat insomnia , short-acting ones (e.g., pentobarbital) to overcome difficulty in falling asleep (one aspect of insomnia), and ultra-short-acting ones (e.g., thiopental sodium) to induce unconsciousness in surgical patients before administration of other anesthetics . Prolonged use of barbiturates may lead to addiction. Sudden withdrawal can be fatal; addicts must be weaned from the drug under medical supervision. Overdoses can result in coma and even death; barbiturates are particularly dangerous, even at normal doses, when combined with alcoholic beverages.