Neuromuscular Relaxants

Question 1

Where do neuromuscular relaxants act?

Answer 1

Neuromuscular relaxants selectively block the nicotinic receptors at the neuromuscular junction

Question 2

How do Nm receptors trigger muscle contraction?

Answer 2

2 ACh are released and bind Nm leading to EPP which will summate into an AP that will propagate down to the T tubules and activate L-type Ca2+ channels which leads to contraction

Question 3

How do non-depolarizing drugs function?

Answer 3

They are competitive antagonists of Nm

Question 4

How do depolarizing drugs function?

Answer 4

They cause prolonged Nm activation and depolarization

Question 5

How can non-depolarizing drugs be overcome?

Answer 5

Excess ACh

Question 6

Do non-depolarizing cross the BBB?

Answer 6

No

Question 7

Where is the receptor reserve the highest in?

Answer 7

Respiratory > Large Limbs > Fine muscles

Question 8

What is the onset of the depolarizing drugs like?

Answer 8

They have a more rapid onset that is metabolized by plasma cholinesterase

Question 9

What is the antidote for non-depolarizing drugs?

Answer 9

Cholinesterase inhibitors

Question 10

What is the antidote for depolarizing drugs?

Answer 10

Phase 1 - Time

Phase 2 - Cholinesterase Inhibitors

Question 11

What are the side effects of non-depolarizing drugs?

Answer 11

Non analgesic
Apnea
Increased HR due to muscarinic block

Question 12

What are the side effects of depolarizing drugs?

Answer 12

Not analgesic
Apnea
Muscle pain fasciculations
HTN
Hyperkalemia

Question 13

Why should Phase 2 block from depolarizing drugs be avoided?

Answer 13

Phase 2 causes desensitization where it re-polarizes but it cannot be depolarized again by ACh

Question 14

What non-depolarizing agent is best for long procedures?

Answer 14

Pancuronium

Question 15

What non-depolarizing agent is best for short procedures?

Answer 15

Mivacurium

Question 16

What non-depolarizing agent is best for renal failure patients?

Answer 16

Rocuronium

Question 17

What non-depolarizing agent is best for liver failure patients?

Answer 17

Pancuronium

Question 18

What non-depolarizing agent is best for medium length procedures?

Answer 18

Vecuronium

Question 19

What is the stretch reflex arc?

Answer 19

1a afferents excite and cutaneous internuncial afferent inhibit extrafusal efferents that stimulate skeletal muscle contraction

Question 20

What is the cause of muscle spasticity?

Answer 20

It is due to the release from inhibition of supra spinal control with heightened alpha and gamma systems and increased activation of facilitory paths

Question 21

Clonus

Answer 21

Reduced ability to lower calcium between stimulations due to increased frequency of stimulation leads to incomplete relaxation

Question 22

What are the curare drugs?

Answer 22

Non-depolarizing agents

Question 23

What are the spasmolytic drugs?

Answer 23

Baclofen
Diazepam
Tizanidine
Dantrolene

Question 24

Succinylcholine effect

Answer 24

Depolarization blockade of muscle nicotinic receptors

Question 25

Succinylcholine indication

Answer 25

Endotracheal intubation | Electro-convulsive shock therapy

Question 26

Succinylcholine elimination

Answer 26

Plasma cholinesterase

Question 27

Pancuronium effect

Answer 27

Non-depolarizing blockade of muscle nicotinic receptors

Question 28

Pancuronium elimination

Answer 28

Renal excretion

Question 29

Pancuronium indication

Answer 29

Adjuvant in surgical anesthesia, sp. abdominal wall relaxation & orthopedic procedures

Question 30

D-tubocurarine use

Answer 30

Prototype - only used in lethal injection. No clinical use.

Question 31

Rocuronium effect

Answer 31

Non-depolarizing blockade of muscle nicotinic receptors

Question 32

Rocuronium elimination

Answer 32

Liver

Question 33

Rocuronium indication

Answer 33

Intubation, muscle relaxation during surgery or ventilation

Question 34

Mivacurium effect

Answer 34

Non-depolarizing blockade of muscle nicotinic receptors

Question 35

Mivacurium elimination

Answer 35

Plasma cholinesterase

Question 36

Mivacurium indication

Answer 36

Intubation, muscle relaxation during surgery or ventilation in pts w/ renal failure

Question 37

Vecuronium effect

Answer 37

Non-depolarizing blockade of muscle nicotinic receptors

Question 38

Vecuronium elimination

Answer 38

Liver metabolism and clearance, renal elimination

Question 39

Vecuronium indication

Answer 39

Adjuvant in surgical anesthesia, sp. abdominal wall relaxation & orthopedic procedures

Question 40

Baclofen target and effect

Answer 40

GABAb agonist | Reduces calcium influx, and therefore reduces the release of excitatory transmitters and substance P in spinal cord

Question 41

Baclofen indication

Answer 41

Spinal Spasticity | Multiple Sclerosis

Question 42

Baclofen toxicity

Answer 42

Drowsiness

Question 43

Diazepam/Clonezapam target and effect

Answer 43

Facilitate GABA mediated pre- synaptic inhibition | Benzodiazepine receptor agonist

Question 44

Diazepam/Clonezapam indication

Answer 44

Spinal Spasticity | Multiple Sclerosis

Question 45

Diazepam/Clonezapam toxicity

Answer 45

Sedation and drowsiness

Question 46

What is the function of GABA?

Answer 46

Reduces neuronal excitability

Question 47

Tizanidine target and effect

Answer 47

Alpha2-adrenergic agonist

Question 48

Tizanidine indication

Answer 48

Spinal Spasticity | Multiple Sclerosis

Question 49

Tizanidine toxicity

Answer 49

Drowsiness | Hypotension

Question 50

Dantrolene effect

Answer 50

Blocks calcium release from sarcoplasmic reticulum in muscle, thus interfering with excitation-contraction in the muscle fiber

Question 51

Dantrolene indication

Answer 51

Spasticity | Malignant Hyperthermia

Question 52

Dantrolene toxicity

Answer 52

Muscle Weakness | Sedation

Question 53

What is the important alternative use of dantrolene?

Answer 53

Treating malignant hyperthermia as it can block ryanodine receptors