Msk 17 & 18

Question 1

Which type of muscle relaxant interferes with neurotransmissino at the neuromuscular junction, but lacks central nervous system activity?

Answer 1

Neuromuscular blocking agents

• aduncts in general surgery

Question 2

Which type of muscle relaxant mostly acts on the central nervous system?

Answer 2

Spasmolytic drugs

• treats muscle spasticity caused by CNS disorders

Question 3

Adverse effects of muscle relaxant drugs manifest on what nervous system?

Answer 3

Autonomic

Question 4

In the synaptic cleft, ACh binds to what type of receptors on the motor end plate to generate a EPSP?

Answer 4

Nicotinic

Question 5

What type of drug is a competitive nicotinic receptor antagonists?

Answer 5

Non-depolarizing agents

• curariform drugs

Question 6

What type of drug is a nicotinic receprot agonist?

Answer 6

Depolarizing agents

Succinylcholine

Question 7

What is the sequence of muscle paralysis?

Answer 7

Small, rapidly moving

Large limb & turnk

Intercostals

Diaphragm

Question 8

What is an adverse effect of Pancuronium?

Answer 8

Tachycardia - inhibition of the parasympathetic vaus n.

Question 9

What is the only route of administration for muscle relaxants?

Answer 9

IV

Poor absorption from GI tract

Question 10

Which drug undergoes spontaneous nonezymatic degradation and is preferred for patients with imparied liver and kidney function?

Answer 10

Cisatracurium

Question 11

This drug is used to attenuate muscle relaxation by increasing junctional ACh levels. Used to treat overdose of non-depolarizing neuromuscular blockers. Used at the end of surgery.

Answer 11

Cholinesterase Inhibitors

Question 12

These drugs potentiate muscle relaxing effects. Dosage of synergistic drug must be reduced when used together.

Answer 12

Inhalational anesthetics

Question 13

What type of drug are isoflurane and halothane?

Answer 13

Inhalational anesthetics

Question 14

This drug inhibits ACh release from cholinergic nerves by competing with Ca²⁺. Synergizes with non-depolarizing blockers to potentiate muscle relaxation.

Answer 14

Aminoglycoside antibiotics

Question 15

Gentamicin and tobramycin are examples of what type of drug

Answer 15

Aminoglycoside antibiotics

Question 16

These drugs enhance muscle-relaxing effects

Answer 16

Calcium-channel blockers

Question 17

This non-depolarizing neuromuscular blocker causes moderate histamine release and ganglionic blockade, and is now rarely used as a therapeutic agent.

Answer 17

Tubocurarine

Question 18

This non-depolarizing neuromuscular blocker is vagolytic and causes moderate tachycardia.

Answer 18

Pancuronium

Question 19

This non-depolarizing neuromuscular blocker has the most rapid onset of action and is useful for rapid tracheal intubation.

Answer 19

Rocuronium

Question 20

This depolarizing neuromuscular blocking agent binds to nicotinic receptors at the motor end plate and causes membrane depolarization

Answer 20

Succinylcholine

Question 21

Which depolarizing neuromuscular blocking agent is insensitive to AChE?

Answer 21

Succinylcholine

Question 22

Prolonged depolarization of muscle cell membrane causes_______.

Answer 22

Muscle paralysis

Question 23

An imbalance between descending excitatory and inhibitory pathways results in ______.

Answer 23

Spasticity

Question 24

This depolarizing neuromuscular blocking agent causes transient fasciculations followed by flaccid paralysis. The second phase of this drug causes membrane desensitization to the effect of ACh.

Answer 24

Succinylcholine

Question 25

For succinylcholine elimination, what is the plasma cholinesterase involved?

Answer 25

Butyrylcholinesterase

Question 26

Pt prepared for surgery develops severe hyperthermia, metabolic acidosis, and tachycardia (malignant hyperthermia). The physician immediately requests:

Answer 26

Rapid cooling Control of acidosis Administration of Dantrolene

Question 27

What receptor does Dantrolene bind to?

Answer 27

GABA_B

Question 28

What is the mechanism of Tizanidine?

Answer 28

Centrally acting a₂-adrenoceptor agonist - decreases excitatory NT release in spinal cord

Question 29

a₂ autoreceptors exist where? What does it modulate?

Answer 29

Presynaptic adrenergic neurons Inhibits release of norepinepherine

Question 30

a2 heteroreceptors exist where? Binding to this receptor modulates what?

Answer 30

Presynaptic non-adrenergic neurons Inhibits release of glutamate

Question 31

Tizanidine is metabolized by hepatic \_\_\_\_\_\_\_, and excreted in urine and feces.

Answer 31

CYP1A2

Question 32

Which receptor does Diazepam bind to?

Answer 32

GABA_A Agonist - causes Cl^- influx and hyperpolarization of postsynaptic neurons 17/18.48

Question 33

What are two important drugs for acute local muscle spasm? What is their mechanism of action?

Answer 33

Cyclobenzaprine (Flexeril) Metaxalone (Skelaxin) MOA unknown

Question 34

Cyclobenzaprine (Flexeril) and Metaxalone (Skelaxin) are used in the treatment of acute muscle spasms due to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, not \_\_\_\_\_\_\_\_\_\_\_\_.

Answer 34

local tissue trauma or muscle strains NOT due to CNS disorders!

Question 35

Succinylcholine increases intracellular K⁺ release (causing muscle weakness). Thus, administration is contraindicated in patients with:

Answer 35

Burns Spinal cord injury muscular dystrophy