Exam 1 pharmacology- muscle relaxants

Question 1

neuromuscular blockers

Answer 1

work in periphery

Question 2

spasmolytics

Answer 2

work in CNS

Question 3

NT of NMJ

Answer 3

acteylcholine

Question 4

receptor in NMJ

Answer 4

Nm (nicotinic cholinergic receptor)

Question 5

2 types of neuromuscular blocking drugs

Answer 5

non depolarizing and depolarizing

Question 6

mechanism of depolarizing neuromuscular blockers

Answer 6

Nm agonist that causes persistent depolarization: initial intense muscle contractions
then the muscle doesn’t repolarize, preventing subsequent activation: flaccid paralysis

Question 7

example of depolarizing neuromuscular blocker and what is it used for

Answer 7

succinylcholine, emergency intubation

Question 8

mechanism of non-depolarizing neuromuscular blocking drugs

Answer 8

complete antagonism of Nm, preventing depolarization all together

Question 9

types of non-depolarizing neuromuscular blockers

Answer 9

Isoquinolines: end in urium + d-tubocurarine
steroid derivatives: end in onium

Question 10

examples of non-depolarizing neuromuscular blockers and what they are used for

Answer 10

rocuronium, mivacurium: intubation
vecuronium: surgical anesthesia for ventilation
tubocurarine: long acting

Question 11

sequence of paralysis via non-depolarizing drugs

Answer 11

small muscles, large muscles, diaphragm
- reverse order to regain sensation

Question 12

what are spasmolytic drugs used for? and what causes is problem?

Answer 12

muscle control disorders resulting in tight, stiff, painful muscles
- caused by an upper motor neuron lesion resulting in an imbalance of signals from the brain

Question 13

where/how does diazepam work?

Answer 13

works in the CNS
binds GABAa receptor, facilitating Cl- conductance to hyper polarize nerves

Question 14

Diazepam use

Answer 14

muscle spasms: reduces muscle tone and can cause sedation

Question 15

where/how does baclofen work?

Answer 15

works in the CNS
GABAb receptor agonist, close Ca++ channels and increases K+ conductance to hyperpolarize

Question 16

Baclofen use

Answer 16

reduces spasticity with less sedative effect

Question 17

where/how does tizanidine work

Answer 17

works in the CNS
alpha2 adrenergic receptor agonist (norepinephrine receptor in brain), close Ca++ channels and increases K+ conductance to hyperpolarize

Question 18

Tizanidine use

Answer 18

effective for spasticity
adverse effects: drowsiness, dry mouth, hypotension, asthenia, hepatotoxicity

Question 19

warning for tizanidine use

Answer 19

dose adjust for those with renal or liver impairments

Question 20

where/how does dantrolene work

Answer 20

in the periphery
blocks the RyR receptor, preventing Ca++ release from SR

Question 21

dantrolene use

Answer 21

oral: central spasticity disorders
IV: malignant hyperthermia

Question 22

symptoms of malignant hyperthermia

Answer 22

massive muscle contractions, lactic acid production, increased body temp

Question 23

where/how does botulinum toxin work

Answer 23

in the periphery at NMJ after injecting directly in muscle
- inhibits cholinergic neurotransmission (inhibits exocytosis of ACh vesicles by interfering with docking proteins)

Question 24

botulinum toxin use

Answer 24

can be used wherever those is a cholinergic nerve
can use every 12 weeks
strabismus, tic disorders, facial wrinkles, migraine, stroke, TBI, hyperhydrosis, low back pain, TMJ disorders, anal fissure

Question 25

drug for local muscle spasms

Answer 25

cyclobenzaprine, metaxalone
- relief of acute muscle spasms caused by local trauma or muscle strain
- usually not due to central lesion and not effective for spasticity of central origin