2. Nicotinic Receptor Drugs

Question 1

Nicotinic receptors are the primary ganglionic receptor of the ANS and the primary receptor of the …

Answer 1

Motor end plate

Question 2

What do muscarinic and peptidergic receptors mediate excitatory post-synaptic potentials through?

Answer 2

Hypopolarization

Question 3

What are the catecholaminergic interneurons of sympathetic ganglia?

Answer 3

Dopamine or NE

Question 4

What are catecholaminergic interneurons stimulated by to hyperpolarize the post ganglionic neurons, and through what?

Answer 4

ACh

Alpha adrenergic receptors (D, NE)

Question 5

What is a depolarizing nicotinic ganglionic blocker?

Answer 5

Nicotine

Question 6

What is a competitive nicotinic ganglionic blocker (competes with ACh for receptor)?

Answer 6

Timethaphan

Question 7

What is a noncompetitive nicotinic ganglionic blocker (blocks associated ion channel opening)?

Answer 7

Hexamethonium

Question 8

What is the effect of nondepolarizing (competitive inhibition) NMJ blockers?

Answer 8

• Requires 70% receptor blockade to produce clinical effect = flaccid paralysis

Question 9

What is the primary clinically-used depolarizing NMJ blockers?

Answer 9

Succinylcholine

Question 10

What does succinylcholine bind to?

Answer 10

ACh-NM receptor

Question 11

What may you experience in phase 1 of succinylcholine?

Answer 11

Muscle fasiculations

• Prejunctional stimulate ACh release, but Na-channels are trapped in a refractory state, preventing further stimulation
• Rapidly restored by removal of drug

Question 12

What occurs with slow IV infusion of nicotinic receptor drugs?

Answer 12

Complete flaccid paralysis

(including respiratory mm)

Question 13

What occurs with rapid IV injection of nicotinic receptor drugs?

Answer 13

Upper respiratory paralysis, these muscles are block before peripheral mm and the 1st to recover.

Question 14

Which dosing is more clinically relevent in nicotinic receptor drugs?

Answer 14

Rapid IV injection

Question 15

What is the pharmacologic activity of nicotinic receptor drugs on the CNS?

Answer 15

Commonly used with general anesthesia

Question 16

What stimulates histamine release?

Answer 16

Stimulation of nicotinic receptors on mast cells

Question 17

What are histamine related effects?

Answer 17

• Hypotension
• Edema
• Bronchospasm
• Inc in salivary flow

Question 18

What is the duration and elimination of succinylcholine, and micaurium?

Answer 18

Short duration due to degradation via pseudo-cholinesterase in the plasma

Question 19

What is the duration and elimination of Rocuronium?

Answer 19

• Intermediate-acting
  
  • ​atracurium, cisatracurium
  • Vecuronium
• Eliminated via urine or bile due to larger size
• Potency inversely correlates with onset

Question 20

What drug is used for short term tx for muscle spasms, increased nor-adrenergic inhibition within CNS ?

Answer 20

Cyclobenzaprine

Question 21

What muscle relaxant is a benzodiazepine that facilitates GABA’s inhibitory response in the CNS?

Answer 21

Diazepam

Question 22

What muscle relaxant is a GABA agonist that reduces the release of excitatory aminoacids like glutamate in the CNS?

Answer 22

Baclofen

Question 23

What muscle relaxant has CNS inhibitory action?

Answer 23

Tizanidine

Question 24

What muscle relaxant interferes with Ca²⁺ influx, and prevents ACh release?

Answer 24

Botulinim Toxin

Question 25

What muscle relaxant uncouples depol from contraction by preventing Ca²⁺ release from SR?

Answer 25

Dantrolene

Question 26

What are the dental applications for muscle relaxants?

Answer 26

• Mandibular fractures
• Lock jaw
• TMJ
• Tooth grinding

Question 27

What are nicotinic receptors blocked by?

Answer 27

Curare