L5 Hypnotic - Sedatives Flashcards
Sedatives Examples.
1.Diazepam
2.Chlordiazepoxide
3.Nitrazepam
4.Lorazepam
5.Clonazepam
6.Alprazolam
7.chlordiazepoxide
8.Bromazepam
Hypnotics Examples
A. Barbiturates:
Phenobarbital
Zolpidem
Zoleplam
Buspiron
Diazepam
Actions of sedatives & hypnotics?
1.Sedation Reduce anxiety in low doses, cause amnesia
2. Hypnosis If used in high doses
3. Anesthesia If used in very high doses.
4. Anticonvulsant effect. (Diazepam & clonazepam)
5. Muscles relaxation( Diazepam).
6. Respiratory depression & death. In high doses.
7. Tolerance Develops to all.
Mechanism of action of Benzodiazepines
-enhance the GABAergic action of GABA , GABA acts as inhibitory neurotransmitter.
-Facilitates the activity of nGABA A1 to open Chloride channels. Not direct
MOA of hypnotic as barbiturate ?
direct effect on GABA receptors. Prolong opening of the channel associated with GABA binding,
increase conductance.
Sedative Hypnotics can cause?
Acute Intoxication
Therapeutic uses of sedatives ?
1- Anxiety disorder (diazepam & Bromazepam )
2- Muscular disorders Multiple sclerosis & cerebral palsy (diazepam )
3- Amnesia Before anesthesia (Medazolam) injectable.
4- Seizures (Diazepam)
5- Alcohol withdrawal syndrome (Diazepam)
6- Grand-mal epilepsy, status epilepticus, febrile convulsion (Diazepam)
5- Sleep disoreers (Triazolam)
(Not used in alcohol intoxication )
Benzodiazepines (Adverse effects):
cause weakness, hypotonia
Tolerance & apnea
competitive drug antagonist used for reversal of central effects of benzodiazepines (Antidote)?
Flumazenil
But it Can cause:
Agitation, confusion & dizziness.
Drug interaction with BDZs?
antihistaminics and anticholinergic
narcotics, alcohol
SSRI’s and oral contraceptives decrease metabolism of?
BDZs
Phenobarbitone, Secobarbitone,Thiopental Mechanism of action:
inc. GABA,A action, open Cl- channel for longer time, cause dose related overall depression of CNS
Uses of barbiturate:
-Anxiety & insomnia:
Secobarbitone (short-acting & is enzyme inducer for its own self)
• Induction of anesthesia: Thiopental (ultrashort acting)
• Epilepsy: Phenobarbitone (long acting)
Therapeutic uses of barbiturates?
1- Anaesthesia : thiopental
2- Anticonvulsant: Phenobarbitol
3-Anxiety
AEs of barbiturate?
tolerance
porphyria
respiratory depression
Miscellaneous sedatives-hynotics :
(H 1 - antihistamines) : Promethazine
β-blockers: Propranolol
Buspiron
Zoleplam
Z drugs ( Zolpedem-Zoleplam):
-GABA mimetic action كلهم
-Hypnotic used for insomnia/dysomnia كلهم
-Oral , rapid onset كلهم
-Rebound anxiety الاول
-Less abuse potential كلهم
-potentiates the CNS depressant مع الثاني
-1/2 t only 1h
minimal muscles relaxant & anticonvulsant actions الاول
Rifampicin & Cimetidine induce them
Buspiron?
-partial Agonist of 5-HT1A receptors; presynaptic
and dec. release of serotonin x
-has affinity to D2 in brain
-Oral
-Used in generalized chronic anxiety Slow acting
- no marked sedation
-Not suitable for acute panic attacks
-No withdrawal effects or dependence or rebound anxiety
-no muscle relaxant or anticonvulsant
(H 1- antihistamines):
• Diphenhydramine & Promethazine
• Mechanism: Block H1 histamine & M3 receptors.
• Possess anti-emetic and anti-allergic properties.
• Depressant effect on RAS related to sedation.
• Use:
Anxiety, insomnia, vomiting & allergic reactions
• Adverse effects:
• May cause drowsiness the next day
• Dry mouth, constipation & blurred vision
• No withdrawal effects. No dependence & abuse
• β-blockers: • Propranolol (Block β 1 & β2 receptors)
Propranolol
• Relieve mainly autonomic symptoms of anxiety: tachycardia, palpitation & tremors
• Do not reduce psychological & non-autonomic symptoms like fear, worry & muscle tension
Sedative-hypnotic Toxicity related to dose
Drowsiness, amnesia
Renal failure dec. bowl sounds, dilated pupil
Decreased learning , Decreased motor skills
Dec. resp, dec. BP, shock
acute intoxication of sedative hypnotics signs
a. Pupils are normal
b. BP is decreased
c. Respiration is depressed
d. Nystagmus on lateral gaze
e. Confusion
F. Tendon reflexes decreased
G. Slurred speech
H. Coma & shock
I. Risk of Death
