Mouse anti-Barbiturates monoclonal antibody for EIA. Barbiturates belong to the group of medicines called central nervous system (CNS) depressants (medicines that cause drowsiness). They affect GABA receptors (like GHB) and thereby bring about a general inhibition of the activity of the CNS, especially that part of the brain stem which governs the rhythm of waking and sleeping. Some of the barbiturates may be used before surgery to relieve anxiety or tension. The only activating stimuli which are not inhibited by barbiturates are pain stimuli. In addition, some of the barbiturates are used as anticonvulsants to help control seizures in certain disorders or diseases, such as epilepsy. Barbiturates have been used to treat insomnia but if they are used regularly (for example, every day) for insomnia, they are usually not effective for longer than 2 weeks. Barbiturates have also been used to relieve nervousness or restlessness during the daytime. Barbiturates have generally been replaced by safer medicines for the treatment of insomnia and daytime nervousness or tension (benzodiazepines).