1 - Skeletal Relaxants

Question 1

What are the two antispastic agents that are NOT centrally acting?

Answer 1

Dantrolene

Botulinum Toxin A

Question 2

MOA for cyclobenzaprine (Flexeril)?

Answer 2

Cause a depressant effect of serotonergic neurons

Strong anticholinergic and antihistamine properties

Question 3

Cyclobenzaprine (Flexeril) - clinical use?

Answer 3

Acute local muscle spasm

Question 4

Cyclobenzaprine (Flexeril) is ineffective in treating muscle spasm due to:

Answer 4

Cerebral palsy or SCI

Question 5

Cyclobenzaprine (Flexeril) can lower the ___ threshold, especially when combined with tramadol (Ultram)

Answer 5

Seizure

Question 6

Clyclobenzaprine (Flexeril) - AE’s?

Answer 6

1. Drowsiness
2. Dry mouth
3. Urinary retention
4. Confusion (in elderly)
5. SEROTONIN SYNDROME

Question 7

Cyclobenzaprine (Flexeril) - CI’s?

Answer 7

1. AMI
2. MAOI’s
3. ETOH
4. Other CNS depressants

Question 8

Cyclobenzaprine (Flexeril) - pregnancy?

Answer 8

No adverse events observed in animal studies

Question 9

Orphenadrine (Norflex) - MOA?

Answer 9

Analog of BENADRYL

Antihistamine and anticholinergic properties

Euphoric and analgesic effects (unknown mechanism)

Question 10

Orphenadrine (Norflex) - clinical use:

Answer 10

Tx of muscle spasm associated with acute painful musculoskeletal conditions

Question 11

Orphenadrine (Norflex) - AE’s?

Answer 11

Anticholinergic effects (dry mouth, urinary retention, n/v, tachycardia)

Confusion (elderly)

Question 12

Orphenadrine (Norflex) - CI’s?

Answer 12

Glaucoma, pyloric or duodenal obstruction, peptic ulcers, MG, BPH

Question 13

Carisoprodol (Soma) C-IV - MOA?

Answer 13

Blocks interneuronal activity and depresses neuron transmission

Anxiolytic and sedative effects

Question 14

Carisoprodol (Soma) - clinical use?

Answer 14

Relief of discomfort associated with acute, painful musculoskeletal conditions in adults

Short term use (2 to 3 weeks)

Question 15

Carisoprodol (Soma) C-IV - AE’s?

Answer 15

Withdrawal symptoms can occur

Sedation, dizziness, HA, seizures

Confusion (elderly)

Question 16

Carisoprodol (Soma) C-IV - pregnancy?

Answer 16

Adverse events have been observed in animal reproductive studies

Question 17

Metaxalone (Skelaxin) - MOA?

Answer 17

Unknown - general depression of the nervous system

Question 18

Metaxalone (Skelaxin) - Clinical use?

Answer 18

Relief of discomfort associated with acute, painful musculoskeletal conditions

Appears to cause less drowsiness than others

Question 19

Metaxalone (Skelaxin) - AE’s?

Answer 19

Nausea, GI upset, sedation, HA, anxiety

Serotonin syndrome

Confusion (elderly)

Question 20

Methocarbamol (Robaxin) - MOA?

Answer 20

Suppresses spinal polysynaptic reflexes

Question 21

Methocarbamol (Robaxin) - Clinical use?

Answer 21

Adjunctive treatment of muscle spasm associated with acute painful musculoskeletal conditions

Treat muscle spasticity associated with tetanus poisoning

Question 22

Methocarbamol (Robaxin) - AE’s?

Answer 22

Urine discoloration (black, brown, or green)

Drowsiness

Confusion (elderly)

Question 23

Methocarbamol (Robaxin) - CI’s?

Answer 23

IV formulation in pt’s with renal impairment

Caution in hepatic impairment

Question 24

Tizanidine (Zanaflex) - MOA?

Answer 24

Centrally acting alpha-2 agonist

Reduces spasticity by increasing presynaptic inhibition of motor neurons

Question 25

Tizanidine (Zanaflex) - Clinical use?

Answer 25

Muscle spasticity | Short acting agent

Question 26

Tizanidine (Zanaflex) - AE’s?

Answer 26

Drowsiness Dry mouth, HOTN, hepatotoxicity Dosage adjustment for renal or hepatic insufficiency

Question 27

Baclofen (Lioresal) - MOA?

Answer 27

Orally active GABA-mimetic agent at the level of the spinal cord Reduces Ca++ influx Reduces excitatory transmitters INHIBIT release of SUBSTANCE P

Question 28

Baclofen (Lioresal) - clinical use?

Answer 28

Drug of choice for multiple sclerosis As effective is diazepam and causes less sedation

Question 29

Baclofen (Lioresal) - AE’s?

Answer 29

Drowsiness, nausea, confusion Increased seizure activity in epileptic pt’s (must withdraw slowly)

Question 30

Diazepam (Valium) C-IV - MOA?

Answer 30

Benzodiazepine Enhancement of the inhibitory effects of GABA Antispasmotic AND antispasticity

Question 31

Diazepam (Valium) C-IV - clinical use?

Answer 31

Oral formulation used in cerebral palsy, MS, temporary muscle spasms, anxiety disorders, ETOH withdrawal

Question 32

Diazepam (Valium) C-IV - AE’s?

Answer 32

Drowsiness, fatigue, ataxia Dependency and tolerance

Question 33

Diazepam (Valium) C-IV - pregnancy cat?

Answer 33

D

Question 34

Gabapentin (Neurontin) - MOA?

Answer 34

Inhibition of voltage-dependent Ca++ channels Analog of GABA

Question 35

Gabapentin (Neurontin) - clinical use?

Answer 35

Generalized tonic-clonic seizures Neuropathic pain and post herpetic neuralgia pain Diabetic neuropathy (off-label)

Question 36

Gabapentin (Neurontin) - AE’s?

Answer 36

Drowsiness, fatigue, dizziness, HA, wright gain Dose adjustment for renal/hepatic insufficiency

Question 37

Pregabalin (Lyrica) C-V - MOA?

Answer 37

Inhibition of voltage-dependent Ca++ channels GABA derivative

Question 38

Pregabalin (Lyrica) C-V - clinical use?

Answer 38

Partial onset seizure (adjunct) Non-epileptic neuropathic pain associated with: diabetic neuropathy, fibromyalgia, restless leg syndrome, social phobia

Question 39

Pregabalin (Lyrica) - AE’s?

Answer 39

Drowsiness fatigue GREATER THAN Gabapentin Dizziness, weight gain, sexual dysfunction

Question 40

Pregabalin (Lyrica) C-V - discontinuation symptoms?

Answer 40

Insomnia, nausea, HA, diarrhea

Question 41

Dantrolene sodium (Rynodex) - MOA?

Answer 41

Reduces skeletal muscle strength by interfering with excitation-contraction coupling in the muscle fibers

Question 42

Dantrolene sodium (Rynodex) - clinical use?

Answer 42

IV DOC for tx of malignant hyperthermia (MH) Oral - spasticity d/t SCI, stroke, MS Not indicated for spasms d/t rheumatic d/o’s

Question 43

Dantrolene sodium (Rynodex) - AE’s?

Answer 43

Muscle weakness, sedation, hepatotoxicity

Question 44

Non-cosmetic uses for botulinum toxin?

Answer 44

Chronic migraines (2nd line agent) Cervical dystonia Blepharospasm

Question 45

BLUF on toxin A:

Answer 45

Slower onset Longer duration of efficacy Less pain of injection

Question 46

BLUF on toxin B:

Answer 46

Faster onset Shorter duration of efficacy More painful injection site Generally for cervical dystonia only