Barbiturates

Drugs that act as central nervous system (CNS) depressants. They produce a wide spectrum of effects from mild sedation to anaesthesia. Some barbiturates are used to treat convulsions.
Found on http://thewellnessshop.co.uk/healthandwellbeing/glossary.html

Barbiturates

a group of sedatives that reduce activity in the brain; are habit-forming and are possibly fatal when taken with alcohol
Found on http://www.medichecks.com/glossary.cfm?ltr=B
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