centrally acting skeletal muscle relaxants , dantorlene botulinum toxin Flashcards
1
Q
Name the centrally acting skeletal muscle relaxants
A
Diazepam (Benzodiazepene)
Tizanidine (α2 agonist)
Baclofen
2
Q
Diazepam
A
-Benzodiazepine (“long tapering flag”)
- increase frequency of oppening of the chloride ion channel
- binds at allosteric site on GABA-A receptor which is a chloride channel and potentiates GABA effects →Cl- influx →hyperpolarization→less neuronal excitation
- indicated for spasticity induced by neurological disorders (e.g. MS)
- produces sedation at required dose for reduction of muscle tone
- can induce withdrawl affects
3
Q
Tizanidine
A
-α2 agonist
- inhibits release of excitatory Amino acids thus re-inforcing both pre/postsynaptic inhibition in the spinal cord
- indicated for spasticity induced by neurological disorders (e.g. MS)
- produces sedation at required dose for reduction of muscle tone
- can induce withdrawl affects
4
Q
Baclofen
A
- GABA-B agonist
- GABA-B receptor is a K+ channel →increase K+ influx →hyperpolarization →Ca+2 ion influx decrease → decrease release of excitatory NTs
- rapid ,complete absorbtion after oral adminstration
- used for spasticity induced by neurological disorder (e.g. MS)
- less sedative but also less effective than Diazepam
- enhances sedative/resp dep. effects of opiates
5
Q
Dantrolene
A
- block RYR1 receptor → decreasing free intracellular calcium concentration.
- treats malignant hyperthermia which is a condition resulting from defective RYR receptors in the Sarcoplasmic reticulum
- useful for spinal injuries ,spasm after stroke
- may cause severe liver toxicity
6
Q
Botulinum toxin
A
- exotoxin of clostridium botulinium
- controls release of Ach from vesicles by binding to synaptobrevin
- treats ophthalmic / local muscle spasms
- local facial injection are used for treatment of wrinkles
- present on honey - shouldn’t be given to children < 1 y.o.
- may cause flaccid paralysis
