CNS-Definition, Classification, Different classes of drug acting on CNS
General Anesthetic- Definition, Stages of anesthesia, Classification
Anesthetic drug- Thiopentone sodium, Ketamine, Propofol detailed study
4. A system that controls all
the activities of the body.
The nervous system also allows you to react to a stimulus.
The nervous system is made of:
1. The brain
2.The spinal cord
3. The neurons
5. The Central Nervous System is made of the brain
and the spinal cord.
The Central Nervous System controls everything
in the body.
6. • Depending upon drug action CNS acting drugs may
grouped as
1. General
Anesthetics
2. Hypnotics and
sedatives
3. Anticonvulsants
5. Antipsychotic
4. Antidepressants
7.
8.
9. 1. General Anesthetics
A drug that brings about a reversible loss of
consciousness.
These drugs are generally administered by an
anesthesiologist in order to induce or maintain general
anesthesia to facilitate surgery.
10.
11. GA brings about descending depression of CNS starting
from cerebral cortex, basal ganglia, the cerebrum &
finally spinal cord.
The important features of general anaesthesia are:
1) From Loss of all sensation, especially pain.
2) Sleep (unconsciousness) and amnesia.
3) Immobility and muscle relaxation.
4) Abolition of somatic and autonomic reflexes.
These drugs are used in surgical operations to induce
unconsciousness and there abolish the sensation of the
pain.
12. Stages of General Anaesthesia:
1. Analgesia (Stage I):
The stage of analgesia lasts from onset of drowsiness to
loss of eyelash reflex (blinking when the eyelash is
stroked).
The patient is considered unconscious at the end of stage.
2. Excitement (Stage II):
The stage of excitement is characterized by agitation
delirium.
During this stage, salivation may be copious.
Heart rate and respiration may be irregular.
Induction agents are designed to move the patient
through this undesirable quickly.
3. Surgical Anesthesia (Stage III): This stage is divided
into four planes and is the target depth for the procedure.
17. Uses:
1) It is administered intravenously for the production of
complete anesthesia for short duration.
2) When given by rectal route as solution, suspension
or suppository it is used as basal anaesthetic.
3) It is also used as a sedative, hypnotic and
anticonvulsant.
Storage and Stability: Thiopental remains stable
and sterile for 6 days at 22°C and 45 days at 5°C with
a loss in potency of less than 7%.
Formulations: Injection, solution, suppositories.
Brands: Thipen, Anesthal, Pentothal, Thiosol.
19. Uses:
1) It is a dissociative anaesthetic as it produces unpleasant
hallucinations and strong feelings of dissociation from
the environment.
2) It is a rapidly acting nonbarbiturate general anaesthetic
that produces anaesthesiaand is characterized by
profound analgesia.
Storage and stability: Ketamine solutions were chemically
stable for periods ranging from 7-180 days when stored at
4°C or 25°C.
Formulations: Injection
Brands: Aneket, Anket, GB -Ket, Hypnoket, Keta
21. Uses:
1) Propofol is the mostly commonly used parenteral
anaesthetic agent.
2) Its rapid onset and reversal of action, and in intensive
care units (ICUS) for maintenance of coma .
3) It induces the sedation and hypnosis during
anaesthesia.
4) Propofol facilitates inhibitory neurotransmission
mediated by gamma-aminobutyricacid (GABA)
Storage and stability: Propofol undergo oxidative
degradation in the presence of oxygen and is therefore
packaged under nitrogen to eliminate this degradation
path. Store between 4 & 25°C
Formulations: Injection
Brands: Celofol, Diprivan Injection, Hypro, Neorof,
Profol.
