skeletal muscle relaxants Flashcards
What are the 3 classes of skeletal muscle drugs for the PNS?
Depolarizing
Non-depolarizing
Direct acting
What are the 2 nervous systems skeletal muscle relaxants work?
PNS (at NMJ at N2 receptors)
CNS (block spinal cord stimulation)
What are the depolarizing drugs for PNS skeletal muscle relaxant?
Succinylcholine
What are the non-depolarizing drugs for PNS skeletal muscle relaxants?
Tubocurarine
Metocurine
Pipecuronium
How do the centrally acting skeletal muscle relaxants work?
Inhibit contraction by blocking conduction within spinal cord by reducing # of impulses that cause contraction
What are the direct acting drugs for PNS muscle skeletal relaxants and the clinical indications?
Dantrolene
PO (orally only)
For muscle spasticity, specifically in people with impaired neuromuscular junctions
What do the CNS muscle relaxants NOT do?
Interfere with nicotinic II receptors
What are the indications for CNS muscle relaxants?
Injured or pulled muscles, spastic muscles or muscle strain
How does succinylcholine work?
2 steps: #1 - attached to N2 receptors and depolarizers #2 - then changes the shape of the receptor so it no longer recognizes ACH
What 4 drugs are CNS skeletal muscle relaxants?
Baclofen
Cyclobenzaprine (flexeril)
Methocarbamol
Carisoprodol
Why is succinylcholine so specially used in surgery?
Short half life
Administered IV only
What are the clinical indications for PNS depolarizing and non-depolarizing drugs?
- short surgical procedures
- longer abdominal surgical procedures
- electroconvulsive shock therapy
What are the side effects of PNS depolarizing and non-depolarizing drugs?
- Hypotension
2. Vasodilation (from histamine release)
What are the adverse effect of PNS depolarizing and non-depolarizing drugs?
- Bronchospasms
- Respiratory Arrest
- Arrthymias
- Malignant Hyperthermia
What is the NT that stimulates N2 receptors?
ACH - acetylcholine
