Skele Muscle Relaxants

Question 0

The antagonistic nondeplolarizing neuromuscular muscle relaxants are divided into two categories. Name the 4 drugs in the Benzylisoquinolines

Answer 0

Tubocurarine (prototype)
Atracurium
Cisatracurium
Mivacurium

-curium

Question 1

What are the two broad categories of skeletal muscle relaxants? Each of their two major subcategories?

Answer 1

Neuromuscular blockers: antagonists(nondepolarizing) and agonists (depolarizing)

Spasmolytics: chronic spasm and acute spasm

Question 2

The antagonistic nondeplolarizing neuromuscular muscle relaxants are divided into two categories. Name the 3 drugs in the ammonio steroids

Answer 2

Pancuronium
Rocuronium
Vecuronium

-uroniums

Question 3

Name the only depolarizing neuromuscular blocker muscular relaxant

Answer 3

Succinylcholine

Question 4

Which two drugs can be used to overcome the competitive neuromuscular block caused by nondeplolarizing muscular relaxants?

Answer 4

Neostigmine and edrophonium

AchE inhibitors

Question 5

Which muscle relaxant first causes fascications before eventually resulting in flaccid paralysis?

Answer 5

Succinylcholine (depolarizing - lots of activation first, then no more neurotransmitter)

Question 6

What is the preferred method of delivery for neuromuscular blockers? Why?

Answer 6

IV or IM

Highly polar and poorly lipid soluble (don’t cross membranes - inactive if given orally)

Question 7

What is the only short acting neuromuscular blocker muscle relaxant?

Answer 7

Mivacurium

Question 8

Name the two long acting neuromuscular blocking muscular relaxants

Answer 8

Tubocurarine

Pancuronium

Question 9

How does renal excretion compare to hepatic excretion in terms of half life and duration of action?

Answer 9

Drugs excreted by liver typically have shorter half lives and shorter durations of action (think first pass metabolism). Kidney excreted drugs have longer half lives and durations of action

Question 10

Which nondepolarizing neuromuscular muscle relaxant is good for use in patients with hepatic or renal failure? Why?

Answer 10

Atracurium/Cisatracurium

They are eliminated spontaneously and don’t require metabolism by kidney/liver

Question 11

After treatment with a nondepolarizing neuromuscular blocking muscle relaxant, patient experiences hypotension and seizures. What drug is responsible? What is an alternative treatment?

Answer 11

Atracurium has a metabolite that is responsible (laudsnosine)

Cisatracurium has less side effects

Question 12

Which is the nondepolarizing neuromuscular blocking muscle relaxant has the most rapid onset and is a good alternative to succinylcholine for rapid intubation?

Answer 12

Rocuronium

Question 13

Patient after a procedure required mechanical ventilation due to a rare defect in their butyrylcholinesterase enzyme. What two muscle relaxants could be responsible for this?

Answer 13

Succinylcholine and mivacurium

Both degraded by butyrylcholinesterase

Question 14

Name the major side affect of the benzylisoquinolines and ammonio steroids (subgroups of nondepolarizing neuromuscular blocking muscle relaxants)

Answer 14

Benzy: hypotension and histamine release
Tubocurarine(worst), mivacurium, and Atracurium

Ammonio: arrhythmia due to muscarinic blockade

Question 15

After a procedure a patient complains of muscle pain. What neuromuscular blocking muscle relaxant did he probably receive?

Answer 15

Succinylcholine - depolarizing so fasciculations first - contraction can cause pain

Question 16

Which muscle relaxant is contraindicated in burn patients? Due to what side effect?

Answer 16

Succinylcholine

Hyperkalemia (worsened in burn patients and released during depolarization)

Question 17

Which muscle relaxant can increase intraocular and intragastric pressures?

Answer 17

Succinylcholine

Question 18

Treatment for malignant hyperthermia?

Answer 18

Dantrolene

Question 19

Which muscle relaxatant has effects at both the Nn and Nm receptors?

Answer 19

Succinylcholine

Question 20

Which two muscle relaxants can cause hypotension through histamine release?

Answer 20

Tubocurarine and mivacurium

Slight effects by Atracurium and succinylcholine

Question 21

Which three classes of drugs must be used with caution when giving neuromuscular blocking muscle relaxants due to their ability to enhance the blockade?

Answer 21

Inhaled anesthetics
Aminoglycosides
Tetracyclines

Question 22

In terms of the neuromuscular blockade, give two conditions that can increase it, and two conditions that are resistant to it

Answer 22

Increase: myasthenia gravis and advanced age (dec drug clearance)

Resistant: burn patients and upper motor neuron disease (due to proliferation of extrajunctional receptors)

Question 23

What drug can be used to prevent the bradycardia that follows a procedure using a neuromuscular blocker?

Answer 23

Glycopyrrolate (muscarinic antagonist) - usually comes in same vial as edrophonium which reverses the blockade

Question 24

Which spasmolytic is an agonist of GABAa receptors in the CNS?

Answer 24

Diazepam

Question 25

Which spasmolytic is an agonist at GABAb receptors in the CNS?

Answer 25

Baclofen

Question 26

Which spasmolytic is an alpha 2 agonist is CNS?

Answer 26

Tizanidine

Question 27

Which spasmolytic increases GABA release in the CNS?

Answer 27

Gabapentin

Saw this one in epilepsy and neuropathic pain treatments

Question 28

Which spasmolytic is an agonist of both GABAa and GABAb in the CNS?

Answer 28

Progabide

Question 29

Name a non-GABA inhibitory neurotransmitter in the CNS that can be used as a spasmolytic

Answer 29

Glycine

Question 30

Name two spasmolytics that are new drugs for the treatment of ALS

Answer 30

Idrocilamide and riluzole

Question 31

Name the three spasmolytics that act directly on the skele muscle as opposed to having central effects

Answer 31

Dantrolene
Botulinum toxin
Cyclobenzaprine

Question 32

Which spasmolytic can be used in the treatment of cerebral palsy?

Answer 32

Botulinum toxin

Question 33

Which spasmolytic is used for the relief of acute muscle spasm caused by local trauma or strain and can cause sedation and sometimes transient visual hallucinations?

Answer 33

Cyclobenzaprine