B - 9. Centrally acting skeletal muscle relaxants (spasmolytics). Dantrolene. Botulinum toxin

Question 1

Central muscle relaxants: names and their function

Answer 1

Baclofen (GABA-B agonist)

For acute spasm
Tolperisone (blocks voltage gated Na+ and Ca++ channels in brainstem)
Diazepam (benzodiazepine, increases GABA-A effect)
Tizanidine (central a2 adrenergic agonist)

Question 2

Peripheral muscle relaxants: names

Answer 2

Dantrolene

Botolinium toxin

Question 3

Dantrolene function and indications

Answer 3

Ryanodine receptor antagonist (RyR1)

• used for hyperthermia after succinylcholine use
• spasmolytic use in CP, MS and post-stroke

Question 4

Botolinium toxin use

Answer 4

From Clostridium Botolinium

Cleaves SNARE proteins -> ACh release is inhibited

Causes local flaccid paralysis if injected, widespread if absorbed systematically

Used in dystonia, spastic muscle disorders, cosmetics