m8 pt. 5 | neuromuscular blocking drugs

Skeletal Muscle Relaxants

Neuromuscular Blocking Drugs are also known as

• pre-junctional blockade

• Post-junctional blockade

2 types under neuromuscular blocking drugs

Pre-junctional blockade

• Acts at the axonal membrane

• Inhibition of the ACh in the nicotinic receptor found in the axon

• biotoxin

• Electrolytes

• Antibiotics

Classifications under pre-junctional blockade

Biotoxin

toxic substance from a living organisms.

Black spider venom

From black widow spider

Botulinum toxin

From Clostridium botulinum bacteria

Tetrodotoxin

From puffer fish

Saxitoxin

From shellfish

Grayanotoxin

From rhododendrons plant

• magnesium

• Calcium

Under electrolytes

Eclampsia

Decrease in calcium may cause

• aminoglycosides

• Polyxins

• Tetracyclinws

• Lincosamides

Antibiotics

• competitive./ non-depolarizing drugs

• Competitive depolarizing drugs

Types under postjunctional blockade

Competitive/ Non-depolarizing drugs

• Peripherally acting muscle relaxant

• Also known as curarizing agents

• Produce flaccid paralysis

• 
  

Chondrodendron tomentosum

used in Africa to hunt animals by using poison arrow which relaxes the muscle.

antihistamine

Premeditation with ______ will reduce tubocurarine whoch will induce hypotension

• tubocurarine

• Chondrodendron tomentosum

Naturally occuring

• alcuronium

• Atracurium

• Vecuronium

• Pancuronium

• Gallamine

• Metacurarine

Synthetic

• Used in operative field, (example is gastric tube)

• Used in Tracheal intubation

• Used for Tetanus especially when paralysis occurs.

• Used in Strychnine poisoning

Use of Competitive/ Non-depolarizing drugs

Competitive Depolarizing Drug

• Calcium is halt therefore Myosin does not bind with actin, leading to relaxation

• Uses is the same with non-depolarizing which is muscle relaxation

SUccinylcholine

• Only commonly used peripherally acting muscle relaxant that is a depolarizing agent.

• Never employ as euthanizing agent

• No antagonists available

Pseudocholinesterase

• Succinylcholine is hydrolyzed by ______

• There is genetically mediated def. of pseudocholinesterase in some strain of sheep

Cattle

_____ are much more susceptible to the effect of succinylcholine