Neuromuscular Blocking Agents and Fibromyalgia/Spasticity - Sweatman Flashcards
What are the isoquinolone derivatives used for neuromuscular blocking?
1) Atracurium
2) Cisatracurium
What are the steroid derivatives used in neuromuscular blocking?
1) Pancuronium
2) Rocuronium
3) Vecuronium
What is the only depolarizing agent used in neuromuscular blocking?
Succinylcholine
What drugs are used to reverse neuromuscular blocking?
1) Edrophonium
2) Pyridostigmine
3) Neostigmine
4) Sugammedex (not approved in US yet)
What receptor do the neuromuscular blocking agents act on?
Nicotinic M receptor –> found on skeletal muscle
What is the physiological role of the nicotinic acetylcholine receptor?
Ligand-gated Na+ channel that opens during depolarization –> 2 Ach bind per receptor
What is the mechanism of action of the non-depolarizing neuromuscular blockers?
Stabilize the closed conformation of the Nicotinic M receptor to prevent Na+ influx
What is the mechanism of action of the depolarizing neuromuscular blocker?
Stabilizes the Nicotinic M channel in the open conformation –> blocks depolarization of the membrane
What is unique about the inactivation of the isoquinolone drugs?
It undergoes hepatic metabolism and Hoffman elimination
What advantage does cisatracurium have over atracurium?
Cisatracurium does no produce the toxic metabolite associated with seizures (laudanosine)
How is succinylcholine metabolized?
Rapidly metabolized by cholinesterase’s in the plasma or liver (5-10 minute duration of action)
What is the major “off target” action of pancuronium and rocuronium?
Cardiac M receptor blocking –> Pancuronium is worse Decreased rate and force of contraction
What are the major adverse effects of succinylcholine?
1) Hyperkalemia
2) Malignant hyperthermia
3) Myoglobinuria
What causes malignant hyperthermia when using neuromuscular blockers?
Uncontrolled release of Ca2+ from sarcoplasmic reticulum
What is the treatment for malignant hyperthermia?
1) Dantrolene
2) Stop giving NM blocker
3) Correct hyperkalemia, acidosis, and cool core temp
What are the major drug-drug interactions (3) of neuromuscular blockers?
1) Volatile anesthetics –> Malignant hyperthermia
2) Aminoglycosides –> Enhanced blockade
3) Local anesthetics –> block pre-junctional neural effect
What are the three acetylcholinesterase inhibitors and their recommended anticholinergics?
1) Neostigmine –> Glycopyrolate
2) Edrophonium –> Atropine
3) Pyridostigmine –> Glycopyrolate
What are acetylcholinesterase inhibitors used for?
To reverse non-depolarizing neuromuscular blockade