Term
|
Definition
| Reduce muscle tone ie in general anaesthesia |
|
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Term
| What ways can SM contraction be inhibited? |
|
Definition
1. Reduce Ca+ release from Sarcoplasmic reticiulum in the muscle (directly acting)
2. Block binding of Ach to Nm receptors at the presynaptic cleft (neuromuscular blockade)
3. Prevent the action in the CNS (centrally acting) |
|
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Term
| What kind of channel is the Nm channel? |
|
Definition
Na+
has 3 phases
1. Acivated
2. Inactivaed
3. Resting |
|
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Term
| What types of Nm blockers (SMR) are there? |
|
Definition
Peripherally acting
- non depolarizing blockers
- depolarizing blockers
Centrally acting |
|
|
Term
Name the non-depolarizing blockers
MOA? |
|
Definition
|
•d-Tubocurarine
•Pancuronium
•Vecuronium
•Mivacurium
competitive antagonists bind to the Nm receptor, preventing Ach binding
|
|
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Term
| Name the depolarizing blocker |
|
Definition
|
|
Term
| How can the non depolerazing SMR blockers be stopped? |
|
Definition
| AchE inhibitor - neostegmine |
|
|
Term
| Neostegmine can revers the actions of which Nm blocker, which one can it not revers? why? |
|
Definition
1. Reversible - non depolerasing blocker - blocks AchE
2. depolarising blocker - receptors have been down regulated/ desensitised due to persistent partial stimulation (fasciculation's are present) |
|
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Term
How are the actions of Succinylcholine stopped?
When are the actions not stopped? |
|
Definition
Pseudocholinesterase in the plasma break it down
Some people have genetic deficiency where their pseudocholinesterase has low affinity to succinylcholine |
|
|
Term
What are the clinical presentations of an individual with pseudocholinesterase enzyme defect?
why? |
|
Definition
apnea/ resp paralysis
succinylcholine in body for longer |
|
|
Term
What are the phases of action SM relaxation?
|
|
Definition
Phase 1 blockade - fasciculation's (only seen is DEPOLARISING!!)
Phase 2 blockade |
|
|
Term
| What are the ADR of Depolarising blockers? |
|
Definition
1. Hyperkalemia
2. Increase IOT - thus contraindicated in people with glaucoma
3. Increase in intra gastric pressure - regurgitaion can occur
4.muscle pain |
|
|
Term
Name the Directly acting SM relaxant
MOA
Use |
|
Definition
Dantroline Sodium
inhibits the release of Ca+ from SR
Malignant hyperthermia |
|
|
Term
What are the 3 cardinal signs of Malignant hyperthermia?
how is it treated? |
|
Definition
Muscle redigity
Increase body temperature
increased CK levels
Due to uncontrolled release of Ca+ - Dantroline sodium is adminstered |
|
|
Term
Name the centrally acting SM relaxants
MOA
Use |
|
Definition
|
Diazepam (Benzodiazepine),
Baclofen (GABA mimetic),
Tizanidine (a2 agonist inhibiting glutamate release)
sports injuries, back aches etc.
|
|
|
Term
What is the MOA of Botolinum
Uses? |
|
Definition
blocks Ach from being released
–Cerebral palsy (to reduce spasticity )
–Sternocledo mastoid tumor
–Blepharospasm
–Strabismus, cosmetics
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