Barbiturate

Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, hypnotics, and anticonvulsants. Barbiturates also have analgesic effects; however, these effects are somewhat weak, preventing barbiturates from being used in surgery in the presence of other analgesics (opioids or volatile anesthetics such as halothane). In mice, barbiturates are hyperalgesic, increasing the sensitivity to pain.

Barbiturates have addiction potential, both physical and psychological. They have largely been replaced by benzodiazepines in routine medical practice, particularly in the treatment of anxiety and insomnia, due to the significant decrease in risk of overdose and the lack of an antidote for barbiturate overdose. Despite this, barbiturates are still in use for various purposes: in general anesthesia, epilepsy, treatment of acute migraines or cluster headaches, euthanasia, capital punishment, and assisted suicide. Barbiturates are derivatives of barbituric acid.

Barbiturates such as phenobarbital were long used as anxiolytics and hypnotics, but today have been largely replaced by benzodiazepines for these purposes because of less potential for lethal overdoses. However, barbiturates are still used as anticonvulsants, as para-operative sedatives (e.g., sodium thiopental), and analgesics for cluster headaches and migraines (ex. Fioricet).

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