skeletal muscle relaxant acting on NMJ

Question 1

Non depolarizing muscular relaxant

Answer 1

• competitive antagonists preventing Ach to depolarize the muscle cells
• at higher doses they produce more intense motor blockade

1st -muscles of face,eyes
2nd -finger,limbs neck trunk
3rd-intercoastals , diaphragm

• useful for anesthesia and facilitation of intubation
• can be reversed by **Neostigmine

Isoquinolone dervatives -**

• Tubocurarine
• Atra-curium
• Cistra-curium

Steroid dervatives -can be reversed by Neostigmine
-Pan-curonium

-Ro-curonium

*have vagolytic effect +enhance NE release

Question 2

Depolarizing muscle relaxant

Answer 2

• depolarize muscle cells similarly to Ach however they are more resistant to degradation by AChE therefore n-AChR is incapable of transmitting further impulses because of the resistance to depolarization
• can lead to flaccid paralysis
• During phase I the reaction is irreversible
• useful for rapid endotracheal intubation or during electroconvulsive shock