Nicotinic Acetylcholine Receptors

Question 1

Nicotinic Acetylcholine Receptors (nAChRs)

Answer 1

Mediate neurotransmission at Neuromuscular junction and Autonomic ganglia.

Question 2

Ganglionic nAChRs

Answer 2

Nicotinic receptor activation causes depolarization of the nerve cell.
-Ganglionic action potential is generated when excitatory postsynaptic potential (EPSP) threshold is reached at the post Ganglionic neuron.

Question 3

True or False: Nicotinic agonist cause activation of both para- and sympathetic gangli.

Answer 3

True

The effects on the Cardiovascular System are Sympathomimetic
The effects on the GI and Urinary tract are Parasympathetic

Question 4

True or False: All nAChR are subject to both depolarizing and non-depolarizing blockade.

Answer 4

True

Question 5

What is a biphasic display in Nicotinic agents?

Answer 5

The effect of nicotine are going to depend on the dose.

Small dose: Stimulate
Large dose: A blockade is followed after the stimulation

Question 6

Describe the two phases of depolarizing Blockade

Answer 6

Phase I: Continued presence of the agonist prevents electrical recovery of the postjunctional membrane.

Phase II (Desensitization): Continued agonist occupancy is associated with return of membrane voltage to the resting level but effect of agonist is desensitized.

Question 7

True or False: Cigarette smoking is clearly the largest single preventable cause of illness and premature death in the US.

Answer 7

True

Question 8

At low concentrations, which receptor of nicotine will have higher affinity?

Answer 8

Neuronal

Question 9

How does Nicotine addiction occur?

Answer 9

Nicotine activates the release of dopamine in the mesolimbic system. However, chronic exposure leads to decrease the release of dopamine (desensitization)

Question 10

What are the treatment for acute nicotine poisoning?

Answer 10

Atropine for ganglion stimulation

Diazepam for Central stimulation

Question 11

What are approaches to help patients to stop smoking?

Answer 11

-Replacement Therapy
-Varenicline: a partial agonist of CNS nAChRs
-Bupropion: non-competitive antagonist of nAChRs.

Question 12

Ganglionic Blocking agents

Answer 12

Nicotine and ACh can produce depolarizing Ganglionic block if amplified with a cholinesterase inhibitor.

Question 13

What Ganglionic blocking drug was used to treat Tourette’s syndrome?

Answer 13

Mecamylamine: a non-selective and non-competitive antagonist of nAChRs.

Question 14

What are Neuromuscular blocking agents used for?

Answer 14

Muscle relaxation
-Anesthetic or control muscle spasms.

Question 15

What adverse effects is commonly cause by Tubocurarine, Mivacurium, Atracurium, and Succinylcholine?

Answer 15

Increase histamine release

-Depolarizing agents like succinylcholine can release K rapidly from intracellular sites.

Question 16

How can we treat Neuromuscular Blocking agents adverse effects?

Answer 16

With AChE inhibitors but they will not reverse depolarizing neuromuscular blockade.

Question 17

What are drug-drug interactions from Neuromuscular blocking agents?

Answer 17

-Halogenated anesthetics
-Aminoglycoside antibiotics
-Calcium Channel Blockers
-Cholinesterase inhibitors

Question 18

Long acting competitive blocking agents

Answer 18

d-Tubocurarine: 80 minute duration. It produces histamine release and it’s an active compound of Curare.

Question 19

Intermediate acting competitive blocking agents

Answer 19

Atracurium: 45 min duration y no se metabolizes en el hígado.

Atracurium and cisatracurium matabolism results in production of laudanosine (epileptogenic)

Question 20

Which of the two produces lower concentrations of laudanosine? Atracurium or Cisatracurium

Answer 20

Cisatracurium

Question 21

Short acting competitive blocking agents

Answer 21

Mivacurium: 15 a 21 min duration

Question 22

Succinylcholine

Answer 22

Short acting (6-11 min) because of butyrylcholinesterase but persist in the neuromuscular junction because of their resistance to AChE.

Fastest onset and shortest duration of action of all muscle relaxants. Does not produce unconsciousness or anesthesia.

Question 23

Succinylcholine Adverse Effects

Answer 23

-Hyperkalemia
-Malignant Hyperthermia
-Muscle soreness

Question 24

Botox

Answer 24

Blocks ACh release at neuromuscular junctions

Question 25

Botox treatments

Answer 25

-Ocular conditions
-Spasms
-Dystonias
-Cerebral palsy for children
-Reduce wrinkles (only temporary)