Antispastic agents (muscle relaxants)

Question 1

Antispastic agents - 7 drugs

Answer 1

Baclofen
Tizanidine
Cyclobenzaprine, orphenadrine.
Carisoprodol
Dantrolene
Botox

Question 2

Baclofen - indications

Answer 2

Severe spasticity (MS & ALS)

Question 3

Tizanidine - MOA

Answer 3

Blocking nerve impulses through presynaptic inhibition of motor neurons. Decreases spasticity without reduction of muscle strength.

Question 4

Tizanidine - indications

Answer 4

Spasticity of MS

Question 5

Cyclobenzaprine, orphenadrine - MOA

Answer 5

Centrally mediated effects on catecholamine reuptake, antimuscarinic and antihistaminergic receptor actions

Question 6

Cyclobenzaprine, orphenadrine - Indications

Answer 6

Short-term management of muscle spasms caused by acute painful, musculoskeletal conditions. (not effective in MS, ALS or cerebral palsy)

Question 7

Carisoprodol - indications

Answer 7

Short-term treatment of muscle spasms caused by musculoskeletal conditions

Question 8

Dantrolene - MOA

Answer 8

Blocks release of calcium ions from SR of muscle fibers. Direct muscle relaxation.

Question 9

Dantrolene - indications

Answer 9

Malignant hyperthermia (life-saving) triggered by halogenated anesthetics. Neuroleptic malignant syndrome after high-potency neuroleptic. Spasticity from many disorders (stroke, paraplegia, cerebral palsy, MS).

Question 10

Botox - MOA

Answer 10

Paralyses muscles by blocking release of acetylcholine on presynaptic side of the muscle end-plate junction

Question 11

Botulinum toxin A - indications

Answer 11

Upper-limb spasticity after stroke. Cervical dystonia and other PD symptoms. Strabismus, blepharospasm (eyelid spasms), urinary incontinence after spinal cord injury (overreactive detrusor muscle)