13. Centrally acting skeletal muscle relaxants (spasmolytics). Dantrolene. Botulinum toxin

Question 1

Centrally acting skeletal muscle relaxants

Answer 1

Drugs for …
plasticity (in chronic condition) only
acute muscle spasm
both acutely and for spasticity

Question 2

Drugs for plasticity only

Answer 2

Baclofen

Question 3

Drugs for acute muscle spasm

Answer 3

unknown mechanism
Mephenesin
Guaiphenesin
Chlorzoxazone

Question 4

Drugs for both acutely and for spasticity

Answer 4

Benzodiazepine - Diazepam
Tizanidine
Tolperisone
Carisoprodol

Question 5

Baclofen

Answer 5

GABAB agonist
reduces pain in spasticity
inhibiting release of substance P in the spinal cord
rapid and complete absorption P.O

Question 6

Diazepam

Answer 6

Acts on GABA -A synapses

metabolized by CYP 1a2

Question 7

Tizanidine

Answer 7

α2 agonist
inhibits nociceptive transmission in the spinal cord dorsal horn
metabolized by CYP 1a2

Question 8

Carisoprodol

Answer 8

metabolite of meprobamate

Question 9

Botulinum toxin

Answer 9

ACh release inhibitor (VAMP + SNAP inhibitor)

Question 10

Dantrolene

Answer 10

inhibits Ca++ release in skeletal muscle
for malignant hyperthermia
adverse effect: Hepatotoxic