Skeletal Muscle Relaxants

Question 1

What are used in surgery to induce temporary mm paralysis?

Answer 1

Neuromuscular Blockers=Anti-Nicotinic Drugs: Nm

EXAMPLES: Tubocuarine: Lasts duration of procedure and Succinylcholine: during intubation

Question 2

Antispasm Drugs Commonly seen in outpatient for comfort

Answer 2

Flexeril, Paraflex

Question 3

Spasmolytic Drugs used for antispasticity (CNS action)

Answer 3

Baclofen
Diazapen (Valium)–Also used for anxiety
Tizanidine

Question 4

Name the Spasmolytic Drugs used for muscle action-antispasticity

Answer 4

Dantrium: Interferes w/excitiation-contraction coupling by interfering w/Ca flux–causes generalized mm weakness and hepatotoxcity
Botox

Question 5

Major side effect for diazepam/valium

Answer 5

Sedation at doses that reduce spasms

Also so reduced strength, hyotension, cognitive slowing, diminished balance

*Must slowly wean off of this or will have withdrawal sx (convulsions, tremor, cramps, vomiting)

Question 6

Baclofen appears most effective when addressing

Answer 6

Spasticity of spinal origin

*Patients w/stroke often do not tolerate baclofen well

Question 7

Name the pharmacodynamics for each spasmolytic drug (3)

Answer 7

Baclofen: GABA-B agonist, inhibition of monosynaptic and polysynaptic reflexes
Diazepam: GABA-A agonist
Tizanidine: Alpha 2 Receptor Agonist; presynaptic and postsynpatic inhibition of SC

Question 8

Adverse affects of Tizanidine

Answer 8

Tizanidine=antispasmolytic, major adverse effect is HYPOTENSION Also see drowsiness, dry mouth, some weakness–see autonomic effects b/c have some binding to autonomic receptors

Question 9

What drug is used for the treatment of hyperthermia?

Answer 9

Dantrolene (dantrium) a anit-spasmolytic (mm) blocks prolonged mm contraction and resulting heat production. This should be taken if a patient takes succinycholine and experiences hyperthermia due to the anesthesia.

Question 10

Temporarily blocks transmission at NMJ, benefits only lasts for weeks to several months

Answer 10

Botulinum toxin

Question 11

Common Adverse Side Effects with Antispasm drugs (Flexeril, Paraflex, Skelaxin)

Answer 11

SEDATION, confusion, HA, N/V

Question 12

Baclofen involves inhibition of what?

Answer 12

Monosynaptic and Polysynaptic reflexes

Question 13

Dantrium (antispasmolytic drug that works at the mm level) interferes with what mechanism?

Answer 13

Excitiation-contraction coupling by interfering w/ Ca flux

Question 14

Major adverse effect of Dantrium is

Answer 14

WEAKNESS

Pt’s with pulmonary dysfunction or myocardial disease should not use dantrium b/c it interferes w/ SR activity in mm

Question 15

Major adverse effect of

1. ) Dantrium
2. ) Baclofen
3. ) Tizanidine
4. ) Diazapam

Answer 15

1. ) Weakness
2. ) Sedation /ataxia
3. ) Hypotension, dry mouth
4. ) Sedation