Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > MSK Pharmacology 4 & 5 (Skeletal Muscle Relaxants) > Flashcards

MSK Pharmacology 4 & 5 (Skeletal Muscle Relaxants) Flashcards

GOOOAL: To understand how to manage spasticity and spasms in patients with upper and lower motor neuron lesions, respectively.

1
Q

two classes of skeletal muscle relaxants

A

neuromuscular blocking drugs and skeletal muscle spasmolytic drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

uses of neuromuscular blocking drugs

A

to produce muscle paralysis in order to facilitate surgery or artificial ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

purpose of spasmolytic drugs

A

to reduce abnormally elevated muscle tone (spasticity) without paralysis (e.g. baclofen, dantrolene, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

definition of spasm

A

sudden, violent, painful, and involuntary contractions of a muscle or group of muscles (i.e. cramps)

involves motor neurons (balance between musculoskeletal movement and body posture)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

relation of action potentials to neuromuscular junctions (NMJs)

A

action potentials by motor neurons are conducted directly to nerve terminals in muscle fibers that form synapses called neuromuscular junctions (NMJs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

______ is released from the nerve terminal, stimulating ______ receptors on the muscle to produce contraction

A

acetylcholine, nicotinic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

spasticity

A

an increase in the passive stretch resistance of a muscle or muscle group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

physical manifestation of spasticity

A

stiff and awkward movements due to increased muscle tone or contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

duration of spasticity

A

permanent condition and may progress to disabling condition without therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

common causes of spasticity

A

closed head injuries
cerebral palsy
multiple sclerosis
stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

mediator of spasm

A

lower motor neurons (LMNs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mediator of spasticity

A

upper motor neurons (UMNs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

typical causes of spasm

A 
bursitis
dislocation
fracture
epilepsy
herniated disc
hypocalcemia
myositis
neuritis
strains
"whiplash" injuries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

typical causes of spasticity

A 
cerebrovascular accident
closed head injury
hemiplegia
paraplegia
quadriplegia
multiple sclerosis
poliomyelitis
spinal cord trauma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where do neuromuscular blockers work?

A

interfere with transmission at the neuromuscular end plate and are NOT centrally acting drugs (e.g. atracurium, pancuronium, gallamine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where do spasmolytics work?

A

they been traditionally called “centrally acting” muscle relaxants but one member, dantrolene is peripherally acting and has no significant central effects (e.g. baclofen, diazepam, tizanidine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

baclofen (Lioresal)

A

centrally-acting drug used to treat spasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

botulinum toxin type A (Botox)

A

centrally-acting drug used to treat spasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

diazepam (Valium)

A

centrally-acting drug used to treat spasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

tizanidine (Zanaflex)

A

centrally-acting drug used to treat spasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

dantrolene (Dantrium)

A

PERIPHERALLY-acting drug used to treat spasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does baclofen work?

A

acts within the spinal cord to suppress hyperactive relfexes involved in regulation of muscle movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

baclofen is the structural analogue of _____

A

GABA (mimics the actions of GABA on spinal neurons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For which receptor is baclofen selective?

A

GABA B (B for baclofen!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Dr. Ngu’s take home message about the action of baclofen

A

acts at the level of the spinal cord to restore inhibiting tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

therapeutic use of baclofen

A

to reduce spasticity associated with MS, spinal cord injury, and cerebral palsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

For which two condition is baclofen NOT effective?

A

stroke and Parkinson’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

therapeutic effect of baclofen

A

decreases flexor and extensor spasms and suppresses resistance to passive movement (reduction of the discomfort of spasticity and allowing increased performance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Preferred treatment for patients whose spasticity is associated with significant muscle weakness?

A

baclofen instead of dantrolene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

absorption of baclofen

A

generally good

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

time to peak concentration of baclofen

A

2-3 hrs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

onset of action of baclofen

A

variable (hours to days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

half life of baclofen

A

2.5-4 hrs.

34
Q

location of baclofen metabolism

35
Q

location of baclofen excretion

36
Q

Side effects of baclofen are most associated with which body systems?

A

CNS and GI tract (serious adverse effects are rare)

37
Q

effects of baclofen on the CNS

A

CNS depressant
frequently causes drowsiness, dizziness, weakness, and fatigue (most intense during the early phase of therapy and diminish with continued drug use)

38
Q

baclofen contraindications

A

patients should not use alcohol or other CNS depressants because baclofen potentiates the depressant action of these drugs

39
Q

family to which diazepam belongs

A

benzodiazepine family

40
Q

only benzodiazepine labeled for treating spasticity

41
Q

How does diazepam act?

A

acts within the CNS by facilitating GABA-mediated presynaptic inhibition (mimics GABA A at receptors in the spinal cord and brain)

42
Q

use of diazepam

A

in patients with muscle spasm of almost any origin, including local muscle trauma

43
Q

side effect of diazepam

A

sedation (occurs in most patients at the doses required to significantly reduce muscle tone)– minimized by initiating therapy with low doses

44
Q

Preferred drug in patients with marginal strength?

A

diazepam over dantrolene

45
Q

drugs that interact with baclofen

A

alcohol
antihistamines
CNS depressants
MAO inhibitors

46
Q

drug interaction effects with baclofen

A

increased CNS depression, increased risk of hepatotoxicity with combination of chlorzoxazone and alcohol

47
Q

drugs that interact with chlorphenesin (antifungal, antibacterial)

A

tricyclic antidepressants (e.g. amitriptyline)

48
Q

effects of drug interactions with chlorphenesin

A

inc. CNS depression, inc. risk of hepatotoxicity with combo of chlorzoxazone and alcohol

49
Q

location of dantrolene action

A

peripheral (directly on skeletal muscle itself)

50
Q

primary action of dantrolene

A

suppression of calcium release from the sarcoplasmic reticulum (decreases the ability of skeletal muscle to contract)

51
Q

therapeutic advantage of dantrolene

A

minimal effects on smooth muscle and cardiac muscle

52
Q

therapeutic uses of dantrolene

A
  1. spasticity (MS, cerebral palsy, spinal cord injury)

2. malignant hyperthermia

53
Q

side effect of dantrolene

A

may be associated w/ a significant decrease in strength (generalized reduction in ability of skeletal muscle to contract)

54
Q

malignant hyperthermia

A

life-threatening syndrome that can be triggered by any general anesthetic and by succinylcholine, a neuromuscular blocking agent

55
Q

prominent symptoms of malignant hyperthermia

A

muscle rigidity, profound elevation of temp. (heat is generated by muscle contraction secondary to massive release of calcium from the SR)

56
Q

How does dantrolene treat malignant hyperthermia?

A

acts on the SR to block calcium release

57
Q

most serious toxic effect of dantrolene

A

dose related liver damage
liver damage has incidence of 1 in 1,000
death from extensive liver damage has occurred

58
Q

What should be performed prior to and throughout treatment with dantrolene?

A

tests of liver function

59
Q

adverse toxic effects of dantrolene

A 
drowsiness
dizziness
malaise
lightheadedness
insomnia
fatigue
confusion
increased urinary frequency
60
Q

dantrolene drug interactions causing increased toxicity

A

estrogen (hepatotoxicity)
CNS depressants (sedation)
clindamycin (increased neuromuscular blockade)
verapamil (hyperkalemia and cardiac depression)
warfarin
clofibrate
tolbutamine

61
Q

carisoprodol (Soma, Vanadom)

A

centrally-acting drug for acute local muscle spasm (LMNs)

can be addictive

62
Q

chlorphenesin (Maolate)

A

antifungal, antibiotic

centrally-acting drug for acute local muscle spasm (LMNs)

63
Q

chlorzoxazone (Paraflex, Relaxone)

A

centrally-acting drug for acute local muscle spasm (LMNs)

64
Q

cyclobenzaprine (Cycloflex, Felexeril)

A

centrally-acting drug for acute local muscle spasm (LMNs)

injury-related spasms

65
Q

diazepam (Valium)

A

centrally-acting drug for acute local muscle spasm (LMNs AND UMNs)

66
Q

metaxalone (Skelaxin)

A

centrally-acting drug for acute local muscle spasm (LMNs)

67
Q

methocarbamol (Carbacol, Robaxin, Skelex)

A

centrally-acting drug for acute local muscle spasm (LMNs)

high risk in the elderly, can slow HR, cause itchy skin rash and sedation

68
Q

vigabatrin (Sabril)

A

centrally-acting drug for acute local muscle spasm (LMNs)

GABA transaminase inhibitor

69
Q

laundry list of centrally-acting drugs for acute local spasms (LMNs)

A

Carisoprodol (Soma, Vanadom)
Chlorphenesin (Maolate), (anti fungal & anti biotic)
Chlorzoxazone (Paraflex, Relaxone)
Cyclobenzaprine (Cycloflex, Flexeril) (injury-related spasms)
Diazepam (Valium)
Metaxalone (Skelaxin) (strains, sprains)
Methocarbamol (Carbacol, Robaxin, Skelex) (high risk in elderly)
Vigabatrin (Sabril) – a GABA transaminase inhibitor

70
Q

another laundry list of drugs used for acute local muscle spasm

A

Chlorphenesin (contraindicated during pregnancy)
Chlorzoxazone
Metaxalone
Methocarbamol
Orphenadrine (anticholinergic properties)
Carisoprodol
Cyclobenzaprine

71
Q

Drugs used for acute local muscle spasm are promoted for…

A

…the relief of acute temporary muscle spasm caused by local trauma or strain. (yes, this is redundant)

Most act as a sedative or at the level of the spinal cord or brain stem.

72
Q

Which drug is the prototype of the group of drugs used for acute local muscle spasm?

A

cyclobenzaprine (believed to act at the level of the brain stem; has some muscarinic effects such as contraction of the detrusor muscle by the bladder)

73
Q

For which conditions is cyclobenzaprine ineffective in treating muscle spasm?

A

cerebral palsy and spinal cord injury

74
Q

cyclobenzaprine’s protein binding and why it’s significant

A

93%, very high, has the ability to interact with other drugs

75
Q

dantrolene’s protein binding and why it’s significant

A

90%, very high, ability to interact with other drugs

76
Q

effects of orphenadril

A

inhibits H1 receptors (antihistamine), inhibits muscarinic receptors (anticholinergic), inhibits NMDA receptors in CNS, inhibits norepinephrine reuptake (the drug has many uses including treatment of fibromyalgia)

77
Q

baclofen contraindication

A

skeletal muscle spasms caused by rheumatoid arthritis

78
Q

carisoprodol contraindication

A

patients with known hypersensitivity to meprobamate

79
Q

cyclobenzaprine contraindication

A

MI, cardiac conduction disorders, hyperthyroidism

80
Q

dantrolene contraindication

A

active hepatic disease, muscle spasms caused by rheumatoid arthritis

81
Q

tixanidine

A

alpha2 agonist

hypotension, drowsiness, dry mouth

82
Q

botulinum toxin

A

spasticity from cerebral palsy

cosmetics surgery

Pharmacology (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions