L 19

Question 1

How to administer non-depolarizing NM blockers

Answer 1

All are highly ionized and will not be absorbed

Must be injected

Question 2

NM Blockers and the CNS

Answer 2

Being highly ionized, do not cross BBB

Paralyzed but awake

Question 3

How to reverse a NM block

Answer 3

Administer AchE Inhibitors like Neostigmine to increase Ach in cleft

Question 4

Double burst results for non-depolarizing vs depolarizing drugs

Answer 4

Non-depolarizing: Posttetanic potentiation, and a fade

Depolarizing: no fade, no Posttetanic potentiation

Question 5

Succinylcholine

Answer 5

Depolarizing NMJ Blocker
Made of two Ach molecules
Has same effect as Ach, except lasts longer and leads to desensitization=> paralysis
Effects cannot be overcome with AchE Inhibitors because it is non-competitve.
Allows lots of Na into cell, and K out of cell–problematic for hypersensitive people

Question 6

Contraindications for succinylcholine

Answer 6

Children

Question 7

What can increase NMJ blockade?

Answer 7

Inhaled anesthetics (Isoflurane)
Antibiotics
Tetracyclines
Ca channel blockers

Question 8

How will myasthenia gravis patients respond to succinylcholine?

Answer 8

Greater response due to less N receptors

Question 9

How do burn victims respond to non-depolarizing NMJ blockers?

Answer 9

They are more resistant because they have more N receptors. But, succinylcholine is not good for them for the same reason. =>K+ loss from the cell and potentially heart failure.

Question 10

d-Tubocurarine

Answer 10

Non-Depolarizing NMJ blocker

Releases lots of histamine which can cause hypotension and bronchospasm

Question 11

Atracurium

Answer 11

Non-depolarizing NMJ blocker

Releases histamine liked-Tubocurarine

Question 12

Cisatracurium

Answer 12

Non-depolarizing NMJ blocker

Unlikely to release histamine

Question 13

Hexamethonium

Answer 13

Ganglion blocker

Non-depolarizing competitive antagonist

Question 14

Mecamylamine

Answer 14

Ganglion blocker

Enters brain–causes tremor, sedation, altered mentation

Question 15

Effects of ganglion blockers

Answer 15

Block all ANS ganglia, effects depend on dominant tone in tissue
Eye: cycloplegia, mydriasis
BV: orthostatic hypotension (lost symp stimulation)
Heart: tachycardia
GU: urinary retention, no ejaculation/erection
No sweating
ANS drugs will have same or enhanced effect because target organs not blocked, but feedback mechanisms will decrease