Skeletal Muscle Relaxants Flashcards
what do skeletal muscle relaxants do?
Skeletal muscle relaxants will
influence the opening and closing of
the myoneural nicotinic receptors.
how can you reverse non-depolarizing skeletal relaxants?
acetylcholinesterase inhibitor (AchEI)
non-depolarizing skeletal relaxants are what kind of drug?
competitive inhibitors (non-depolarizing drugs can be out competed which is good
what are neuromuscular blockers?
work at the NMJ to cause muscle paralysis
because neuromuscular blockers work at the level of the NMJ how do they impact the CNS?
they do not impact the CNS due to the selectivity of the drugs to the myoneural nicotinic receptors
what are spasmolytics and antispasmodics?
used to reduce muscle spacificty in varity of conditions such as TMD, bruxism and back pain
how do spasmolytics and antispasmolytics work?
block at the level of the spinal cord
where does dantrolene work?
directly on skeletal muscle
D-tubocurarine is a what kind of drug?
competitive inhibitor that blocks at the myoneural nicotinic receptor
nondepolarizing drug (does not allow Na to gain entry to skeletal muscle)
succinylcholine is a ____ drug
depolarizing
how do you know if a drug is a part of the benzylisoquinoline drugs?
have a CUR in the name
what do amino seriods have in the name?
-curonium
Succinylcholine, a depolarizing drug. When compared to acetylcholine, it is….
- More potent and prolonged binding at nicotinic receptor.
- More resistant to degradation by acetylcholinesterases (AchE).
how are NMB drugs given?
IV given when pt is undergoing anesthesia
in benzylisoquinoline drugs what makes them more potent?
more methoxy groups = more potent
Atracurium is no longer in widespread clinical use
because it can breakdown into a product called
laudanosine
what is laudanosine?
slowly metabolized by the liver and can cross the blood-brain-barrier (BBB) which may cause seizures
(use cistatracurium instead)
how are neuromuscular bocking drugs eliminated?
liver though biliary excretion
The benzylisoquinolines are mainly eliminated through what mechanism?
enzymatic hydrolysis of ester bonds and elimination by the kidneys
for NMB how is their clearance related to their action?
drug’s clearance is directly proportional to the drug’s duration of action.
For succinylcholine, it does not get inactivated by acetylcholinesterase
within the synaptic cleft, but will be metabolized by ______ and ________ in the liver and plasma, respectively
butyrylcholinesterase
and pseudocholinestereasese
how long is the duration of action for succinylcholine?
short, around 8 mins due to the rapid metabolism through cholinesterase
if a pt has genetic deficiency of cholinesterase’s what must be avoided?
succinylcholine
what is one risk that can occur with skeletal muscle relaxant?
if you use too much you can cause paralysis of the diaphragm
which muscles get effected first my muscle blockers, which get reactivated first?
smaller muscles first to be blocked and last to recover from block when the anesthetic has been removed
see notes sheet
