Download Sedative Hypnotic

Sedative Hypnotic
-------------------------Sedation: It is a state of drawsiness,calmness & quiteness without producing actual sleep.
Sedative: The drugs that reduce anxiety & exert claming effect.
Hypnotics: The drug which produce drowsiness,encourage the onset & maintainence of sleep.
pharmacological Effect:
........................................
1.Sedation:
2.Hypnosis: normal sleep
REM : dreamy
NREM: sound sleep, duration is increase
3.Anaesthesia: High dose of certain sedative hypnotics depress the CNS
to the potent known as stage III of general Anaesthesia.
Thiopental Na & methahexital are very lipid soluble penetra.
Thiopental Na: induction
diazepum: pre-anaesthetic medication
medazolam,diazepine(it helps to anxiety)
4.Anticonvulsant Effect: Anti epileptic form
clonazepam,diazepam,nitrazepam,lorazepam are selective to be clinically.
5.Muscle Relaxation:(during surgery)
-peripherally
-CNS: diazepam centrally workes best
some sedative hypnotics exert inhibitory effect on polysynaptic reflexes & internuncial transmission
EX- meprobomate,benzodiazepine group
6.Effects on respiratory & cardiovascular function:
** effects on respiration are dose related & depression of medullary respiratory center is the usual cause.
at therapeutic dose,sedative hypnotic can produce significant respiratory depression in patients with
pulmonary disease.
at hypnotic dose,in healthy patients, the effect of sedative hypnotics on respiration are as
changes during natural sleep.
CLINICAL USE :
----------------------1. For Relief of Anxiety: pain disorder
Treatment: Alprazolum(fast acting benzodiazepine)
2. For Insomnia: it results from inadequate treatment of underlying medical condition or psychiatric illness.
the drug selected should be one that provide sleep of fairly rapid onset & sufficient
duration with minimal hangover effect.
the newer hypnotics are zolpidem,zaleplon & eszopiclone are prefered.
Q: why newer drug are prefered?
Ans. they are selective anxiolytic (decrease anxiety)
3.For sedation & amnesia before & during medical & surgical procedure:
EX: Endoscopy,Bronchoscopy
4.Pre Anaesthetic Medication.
5.For treatment of epilepsy & seizure state
6.As a component of balanced anaesthesia
Treatment: Intravenous administration
7.for muscle relaxation in specific neuromuscular disorder
Treatment: meprobomate,benzodiazepine
8.For Rx 07 psychiatry
Treatment: CVS - thrapeutic dose - produce toxicity
CLINICAL TOXICOLOGY:
------------------------------------Direct Toxic Action:
A) CNS Adverse effect:
Low dose- Drowsiness
- Impaired judgement
- Diminished motor skills
- job perforance & personal relationship.
High dose- Lethargy or a state of exhaustion
- breathing problem in pt. with chronic pulmonary diseasewith sleep apnea.
Lethal dose- respiratory depression
- CVS depression
B) Adverse Effect not related to CNS action:
Hypersensitivity reaction
teratogenecity
C) Alteration in drug response:
Tolerance: decrease responsiveness to a drug following repeated exposure.
Physiologic dependence: with the long term use of sedative hypnotics, if doses are
increased, this state develope.
Psychological dependence:
cross dependence - other CNS drug causes neutralization,no effect,
chemical structure,effect,potency are same.
barbiturate,morphine,pathedine - produce tolerance.
TREATMENT OF OVERDOSE:
--------------------------------------------* Airway assesment & maintainence.
* Ventilatory support if necessary.
* NG suction: activated charcoal.
* Flumazenil: competitive antagonist.
FLUMAZENIL
-------------------* It is an active antagonist.
* It is a synthetic benzodiazepine derivative.
* It blocks action of~benzodiazepine
~zolpidem,zaleplon & eszopiclone
but doesn't antagonise the action of barbiturate,meprobomate or ethanol.
Mechanism of action:
-----------------------------Flumazenil binds with BDZ receptor
l
competitve antagonism
reverse thr cns depressant effect of BDZ overdose
( antagonism of respiratory depression is unpredictable )
Adverse Effect:
---------------------*Agitation
*Confusion
*Nausea
*Dizziness
Drug Interaction:
----------------------# Interaction resulting more
Benzodiazepine + New drug = Less drug interaction
Barbiturate = More drug interaction ( due to potency & induce the hepatic microsomal enzyme )
Tolerance:
--------------Decrease responsiveness to drug following repeated exposure.
EX: drug causing tolerence
TYPE:
1)Metabolic- due to chronic administration ( EX- barbiturate )
2)Pharmacodynamic- common changes in responsiveness of CNS
EX- Most of the sedative hypnotics.
Physiological Dependence:
Altered physiologic state that requires continuous drug administration to prevent an abstinence or withdrawl syndrome.
Sign Symptom:
Increase anxiety,insomnia & CNS excitability that may progress to convulsion.
Psychologic dependence:
It is a state that tends to promote compulsive use of the drug.
-Craving to take the drug
-No withdraw symptom
-Doesn't effect the society
Q:Classification of Barbiturate according the duration of action?
Ans:
Ultra short acting --- thiopental Na ----- (with in sec)
short acting ---------- secobarbitone --- (2hrs)
pentabarbitone
Intermediate -------- amylobarbitone -- (4-5 hrs)
butobarbitone
Long ------------------ phenobarbitone--- (6hrs)
Q:Difference between BDZ & new drugs?
Ans:
Newer sedative hypnotics:
Buspirone* Has selective anxiolytic property.It relieves anxiety without causing marked sedative,hypnotic cuphoric effect.
* Undergoes extensive hepatic 1st pass metabolism & form active metabolites.
* Exerts anxiolytic effect by acting as partial agonist at brain 5HT receptor & also have affinity to dopamine D2 receptor
withdrawl symptom
Abuse potential
Interaction within alchol
Adverse effect-Sedation
-Amnesia
BDZ
yes
low
marked
yes
yes
Buspirone
no
zero
slight
no
no