sedative hypnotics

1. SEDATIVE - HYPNOTICS

2. Sedative - Hypnotics
• Sedative: ↓activity, excitement, calms
the patient
• Hypnotic: produces sleep similar to
normal sleep

3. CLASSIFICATION
–SEDATIVE HYNOTICS

4. 1. BENZODIAZEPINES
 Ultra short acting (6hrs) Midazolam, Triazolam
 Short acting (12hrs) Alprazolam
 Intermediate acting (24hrs) Lorazepam,nitrazepam
 Long acting(>24hrs) Diazepam, clonazepam
2. BARBITURATES
 Ultra Short acting Thiopentone
 Short acting Pento barbitone
 Long acting Phenobarbitone
3. Z drugs: Zolpidem, Zopiclone
4.OTHERS: paraldehyde, chloralhydrate

5. 1. BENZODIAZEPINES
 Ultra short acting (6 hrs) Midazolam, Triazolam
 Short acting (12 hrs) Alprazolam
 Intermediate acting (24 hrs) Lorazepam,nitrazepam
 Long acting(>24 hrs) Diazepam, clonazepam
2. BARBITURATES
 Ultra Short acting Thiopentone
 Short acting Pento barbitone
 Long acting Phenobarbitone
3. Z drugs: Zolpidem, Zopiclone
4.OTHERS: paraldehyde, chloralhydrate

6. BENZODIAZEPINES-
DIAZEPAM (Prototype)

7. Mechanism of action of
benzodiazepines

8. GABA: the inhibitory neurotransmitter
Receptor for GABA: GABA A receptor
GABA A receptor: ligand gated ion channel

9. GABA A
receptor
GABA
Cl-
Cl-
MEMBRANE HYPERPOLARISATION & CNS DEPRESSION

10. GABA A
receptor
GABA
Cl-
Cl-
MEMBRANE HYPERPOLARISATION & CNS DEPRESSION
BNZ GABA
Cl-
Cl-
Cl-
Cl-

11. BNZ
Bind to BNZ binding site of the GABAA
receptor(other than GABA binding site)
Facilitates the binding of GABA to GABA A receptor
Increase in the opening of chloride channels
Increased conductance of chloride ions
Membrane hyperpolarisation
CNS depression
GABA facilitatory
action

12. Other drugs acting on the GABA
receptor:
 Barbiturates
 Z agents
 General anaesthetics(inhalational &
intravenous)
 Ethanol

13. Pharmacological Actions
CNS
actions

14. CNS actions
1. Sedation & Hypnosis
2. Anti anxiety
3. Anaesthesia
4. Anti convulsant
5. Anterograde amnesia: midazolam
having good amnesia
6. Skeletal muscle relaxation by acting
on brain & spinal cord

15. ADR
• Drowsiness,confusion,amnesia
• Psychomotor impairment( no Driving)
• Blurred vision,vertigo,vomiting
• Not given during Labour:cause respiratory
depression and hypotonia in newborn called
as floppy baby syndrome

16. USES of BNZ
• INSOMNIA
• Epilepsy
• Anxiety disorders
• Anaesthesia
• Spinal injuries, tetanus

17. 1: INSOMNIA
Rationale: due to its sedative effect

18. BNZ are preferred over
Barbiturates as a sedative hypnotic
due to:
Less distortion of sleep pattern due to
minimal REM supression
Less hangover effects like headache
Less respiratory depression
More safe
Less dependence and Abuse potential

19. 2: EPILEPSY
• Rationale: as it ↑ seizure threshold
• Drugs used : Diazepam,lorazepam,
clonazepam
• Used in seizure disorders like
Status epilepticus :lorazepam/diazepam
Febrile convulsions : Diazepam/lorazepam
For long term Rx of epilepsy: clonazepam

20. EPILEPSY…
• Diazepam not given for long term for treating
epilepsy because:
• Due to its sedative effect
• Due to the development of tolerance to
anticonvulsant effect on long term therapy

21. 3. Anxiety disorders

22. 4: Anaesthesia
• Mainly used in preanaesthetic
medication due to:
 sedative
Amnesic
Anxiolytic effects
• Diazepam,Midazolam,Lorazepam are
used

23. 5: Diagnostic procedures and
small procedures like
endoscopies
Sedative
Amnesic
Anxiolytic effects
• Diazepam,Midazolam,Lorazepam are
used

24. 6: Spinal injuries,tetanus
• By its Central skeletal muscle
relaxant action on brain and spinal
cord it will reduce the spasm
• Diazepam,Clonazepam are used

25. Pharmacokinetics
• All are Lipid souble so got CNS
actions
• no enzyme induction when
compared to barbiturates
• Orally, IV,rectal route
• Not given IM

26. BENZODIAZEPINE ANTAGONIST
FLUMAZENIL
• COMPETITIVE ANTAGONIST
• USED IN BNZ POISONING( DIAZEPAM)

27. BNZ POISONING
GENERAL MEASURES:
• Maintain ABC
• Gastric lavage
SPECIFIC MEASURES:
• Antidote: Inj FLUMAZENIL
0.2mg/min IV
Rationale:
flumazenil is a competitive
antagonist at GABA receptor

28. USES OF BARBITURATES
• THIOPENTONE SODIUM: as
intravenous anaesthetic
• Phenobarbitone: in epilepsy &
neonatal jaundice

29. BARBITURATE POISONING
• Maintain ABC
• Gastric lavage
• No specific antidote
• Alkaline diuresis by sodium bi
carbonate:in alkaline urine barbiturate
(acid) gets ionised and so will not be
reabsorbed and hence will be excreted
• In case of renal failure- dialysis

30. The Z agents/
non benzodiazepine hypnotics
Drugs:
Zopiclone
Zolpidem

31. Z agents…
MOA:
Binds to a site different from BNZ
Faciliates the binding of GABA
Opening of chloride channels
Membrane hyperpolarisation

32. Z agents…
Actions:
Sedative &Hypnotic
Amnesia
but lacks anti anxiety, anti
convulsant & muscle relaxant
property

33. Uses of Z agents
Mainly used in short term insomnia

34. Anxiolytics-drugs for anxiety
Buspirone: 5-HT 1A agonist
Benzodiazepies- diazepam
Beta blockers- Propranolol(reduces
sympathetic over activity)
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35. THANK YOU