Week 3 Pharm-spasmolytics

Question 1

Dantrolene

Answer 1

Direct acting; decrease muscle spasticity by interfering w/ calcium ion release from sarcoplasmic reticulum; no muscle contraction; useful in treating malignant hyperthermia; can cause liver toxicity.

Question 2

Dantrolene acts as a spasmolytic by

Answer 2

Decreasing calcium release from the sarcoplasmic reticulum

Question 3

Botulinum Toxins

Answer 3

Cleave SNARE complex (required for ACh vesicle fusion @ NMJ); A-Face, B-muscle; go after more specific muscle-focal spasticity; response is dose dependent; w/in 24-72 hrs, peak @ 4-6 wks, lasts 2-6 mths; side effect- weakness, pain @ injection site, infxn, dysphagia, respiratory failure, Ab formation

Question 4

Baclofen

Answer 4

GABA-B agonist; treat spasticity, improve mobility in pts w/ MS and other spinal lesions; intrathecally (spinal cord); no cognitive deficits; no global muscle weakness; blocks polysynaptic afferent pathways; acts as inhibitory neurotransmitter or hyperpolarizes primary afferent nerve terminals(b/c ^K+); reduce amt of glutamate or aspartic acids, Ca2+, ACh released

Question 5

Cyclobenzaprine

Answer 5

Similar to tricyclic antidepressants-anticholinergic activity, potentiation of norepinephrine; causes great deal of sedation, confusion, visual hallucinations, releases histamine; relieves muscle spasms through central action @ brain stem level; DOES NOT ACT ON NMJ OR MUSCLE;

Question 6

Tizanidine

Answer 6

Central acting alpha2-adrenergic agonist-pre&postsynapticaly w/in the cord; similar to clonidine; decrease release of excitatory A.A.- leads to inhibition of spinal motor neurons; more drowsiness and sedation than baclofen; no muscle weakness compared to baclofen; decreases BP

Question 7

Spasmolytic agent least likely to cause sedation, muscle weakness or mental confusion is

Answer 7

Baclofen

Question 8

Riluzole and Idrocilamide

Answer 8

Is a benzothiazole- inhibits glutamate transmission, improves energy metabolism in muscles; interferes w/ Na+ channels required for glutamate release; treats ALS & Huntington’s-reduce spasms; extends survival and/or time w/out ventilator; SFXs- asthenia, decreased respiration, pneumonia, vertigo, paresthesia, anorexia, somnolence

Question 9

Gabapentin

Answer 9

Antiepilietic used in pts w/ MS- chemical modification of GABA- doesnt act on it

Question 10

Pregabalin

Answer 10

analog of gabapentin

Question 11

Progabide

Answer 11

GABA-A&B agonist- has active metabolites including GABA itself- blocks receptors

Question 12

Glycine

Answer 12

Inhibitory A.A. NTM- active given orally, readily passes the BBB

Question 13

Pt w/ cerebral palsy suffering from limb spasticity, what is causing this?

Answer 13

unopposed action of spindle afferents

Question 14

Diazepam

Answer 14

Valium- GABA-A positive modulator increases GABA-B receptor action in both the cord and brain; muscle relaxer; diAzepam-GABA-A