Background Sedative-hypnotics are a group of drugs that cause CnS depression Benzodiazepines(bzd) the most commonly a barbiturates used agents a nonbarbiturate nonbenzodiazepine sedative hypnotics( nbnbBackground Sedative-hypnotics are a group of drugs that cause CNS depression. ◼ Benzodiazepines (BZD) ◼ barbiturates ◼ nonbarbiturate nonbenzodiazepine sedativehypnotics (NBNB) the most commonly used agents