Muscle Relaxers and Neuromuscular Blockers Flashcards
Differentiate skeletal muscle relaxers from neuromuscular blockers.
Direct muscle relaxers: blocks release of Ca within the cell and thus blocking contraction
Indirect muscle relaxers: hyperpolarize neurons that innervate muscle groups to decrease spasm
Neuromuscular blockers: block Ach receptors in skeletal muscle system thereby preventing contraction
What is another name for neuromuscular blocking agents?
Paralytics
Which neuromuscular blocking agent differs from the others by its mechanism? Describe its mechanism.
Succinylcholine - depolarizing agent that first stimulates the Ach receptor before blocking it.
What do all the non-depolarizing neuromuscular blocking agents end in? List some examples.
-onium –> rapacuronium, vecuronium, rocuronium
What neuromuscular blocking agent is most likely to be used in rapid sequence intubation and why?
Succinylcholine –> it is rapid on and rapid off
What infectious agent acts by blocking Ach release?
Clostridium Botulinum
In what ways can a patient get acetylcholine overload pathologically?
Tetanus and organophosphates - nerve gas, insecticides
What other types of medications must be given to a pateint that is given a paralytic?
A sedative and possibly an anxiolytic
List two common AEs of neuromuscular blocking agents.
Hypertension and hyperkalemia
Describe the “titrate to four” phenomenon clinicians use to determine an appropriate level of paralysis has been achieved.
A device attached to the wrist that delivers 4 shocks and would normally be followed by 4 arm twitches. The number of twitches out of four that is seen is a way to quantify their level of paralysis.
What drugs can be used to reverse the effects of paralytics and what are the AEs of these reversal agents?
Acetylcholinesterase inhibitors –> GI peristalsis, bradycardia, salivation, etc.
Are acetylcholinesterase inhibitors used to reverse paralytics reversible or irreversible inhibitors?
Reversible –> organophosphates and nerve gasses are irreversible
What acetylcholinesterase inhibitor drugs are used to reverse paralytics and what other disease are they used to treat?
Stigmines - neostigmine, ex –> also used to treat myasthenia gravis
What is a second generation drug used to reverse paralytic agents and what are its advantages?
Sugammadex –> no GI effects because it encapsulates and metabolizes the paralytic agent rather than acting on acetylcholinesterase
List 2 PO skeletal muscle relaxers that are controlled substances in KY and state what control schedule they are.
Carisoprodol and Meprobamate –> C-4
What are the clinical uses for carisoprodol and meprobamate?
Muscle relaxation and some anxiolytic effects
What is the clinical use of cyclobenzaprine and what is its major AE?
Muscle relaxation –> highly sedating and anti-Ach effects
How is cyclobenzaprine toxicity treated and why?
Bicarbonate –> cyclobenzaprine is a first cousin to TCAs
What is the primary clinical use of baclofen?
Given as part of an epidural injection (intrathecal administration)
What two medications are used to treat intractable hiccups and what patients get intractable hiccups?
Baclofen and chlorpromazine (anti-psychotic)
Ventilated pateints get intractable hiccups
Which skeletal muscle relaxer is most likely to be used in a nursing home and why?
Metaxalone because it has reduced anti-Ach effects –> less sedation
Which skeletal muscle relaxer is most likely to cause hypotension and why?
Tizanidine –> chemically related to clonidine
Name a direct acting skeletal muscle relaxer and state two clinical uses.
Dantrolene –> neuroleptic malignant syndrome and malignant hyperthermia
Name 3 other skeletal muscle relaxers we didn’t discuss further in class.
Orphenadrine, chlorzoxazone, methocarbamol
