Sedatives calm patients without inducing sleep by decreasing responsiveness to stimulation. Hypnotics induce and maintain sleep. Barbiturates and benzodiazepines are common sedative-hypnotic drugs. Barbiturates act directly on GABA receptors to facilitate the opening of chloride channels. Benzodiazepines enhance the effects of GABA through binding to GABA receptors. Newer nonbenzodiazepine drugs like zolpidem and zaleplone also act through GABA pathways to produce sedation and hypnosis.

1. SEDATIVE & HYPNOTICS
SEDATIVE- A drug that subdues excitement and
calm the object without inducing sleep.
Sedation refers to decreased responsiveness to
any level of stimulation , is associated with
decreased some motor activity and ideation.
HYPNOTIC- A drug that induce or maintains
sleep.
NOTE- faster onset action drug used as
hypnotics and slower onset of action drug used
as sedatives.

2. CLASSFICATION
 1.BARBITURATE
 A-LONG ACTING-Phenobarbitone, mephobarbitone
 B-SHOT ACTING-Pentobarbitone, butobarbitone
 C-ULTRA SHORT ACTING-Thiopentone,methohexitone
 2.BENZODIAZEPINES
 A-HYPNOTIC-Diazepam,midazolam,alprazolam,lorazepam
,chlorazepam,nitraepam,flurazepam,
• B-ANTIANXIETY-
Lorazepam,diazepam,chlorazepam,alparzolam,
• oxazepam.
• C-ANTICONVULSANT-Diazepam,lorazepam,clonazepam
(ANTIPSYCOTIC)
• NEWER NONBENZODIAZEPINS-
Zolpidem,zopiclone,zaleplone,
• zaleplon,eszopiclone

3.  BARBITURATES-Now they not used to induce sleep or calm the
patient, Bariturates are used in late 1960.only used as general
anesthetic.
 Barbiturates have GABA facilitatory as well as GABA mimetic
actions.
 Pharmacological action-
1-CNS- Sedation Sleep Anesthesia Coma(death)
• MECHENISM OF ACTION- Two subunits alpha and beta onto
GABAa receptor, barbiturate are bind there and
facilitate GABA and opening of chloride channel directly.
• NOTE-Bicuculline is competitive antagonist of GABAa receptor
Picrotixin- Work as a noncompetitive antagonist of GABAa
receptor, act on picrotoxin sensetive sites.
• BENZODIAZEPINES(BZD)- BZD act by enhancing
pre/postsyneptic inhibition through BZD receptor which is an
integral part of GABAa receptor-chloride channel complex
• BZD binds on to alpha and gamma subunits of GABAa-CL
COMPLEX.

4. GABAa-BZD-CHLORIDE CHANNEL COMPLEX AND
BINDING SITES OF BARBITURATES,BZD,NEWER
NONBZD AND FLUMAZENIL(BZD ANTAGONIST)

5. • IMPORTANT POINTS-
• Diazepam is the only BZD which is used as Anxiolytic ,hypnotic,
muscle reaxent ,premedicant ,anesthetic and emergency control
of seizures due to his broad spectrum activity.
• Diazepam active metabolites is oxazepam.
• Midazolam is shortest acting BZD.
• Oxazepam is not metabolized by liver.
• Diazepam is choice in elderly and liver disease patient.
• Beta-carboline is a inverse agonist of BZD site,result impede
GABA actiom.
• FLUMAZENIL-BZD antagonist, it abolishes hypnogenic,
psycomoter, cognitive and EEG effect of BZD.
• USES in To reverse BZD anesthesia, BZD overdose.
• Melatonin AGONIST- MELATONIN and RAMELTEON both are
use as a sleep inducer, both bind to MT1,MT2 receptor.