28
Neuromuscular junction
blocking agents
Learning objectives
Upon completion of this chapter, you should be able to:
1.
Draw and label a neuromuscular junction.
2.
Describe the therapeutic actions, indications, pharmacokinetics, contraindications, most common adverse
reactions and important drug–drug interactions associated with the depolarising and non-depolarising
neuromuscular junction blockers.
3.
Discuss the use of neuromuscular junction blockers across the lifespan.
4.
Compare and contrast the prototype drugs pancuronium and suxamethonium with other neuromuscular
junction blockers.
5.
Outline the care considerations, including important teaching points, for people receiving a neuromuscular
junction blocker.
Glossary of key terms
acetylcholine-receptor site:
area on the muscle cell membrane where acetylcholine (ACh) reacts with a specific receptor site to cause
stimulation of the muscle in response to nerve activity
depolarising neuromuscular junction (NMJ) blocker:
stimulation of a muscle cell, causing it to contract, with no allowance for
repolarisation and re-stimulation of the muscle; characterised by contraction and then paralysis
malignant hyperthermia:
reaction to some NMJ drugs in susceptible individuals; characterised by extreme muscle rigidity, severe
hyperpyrexia, acidosis and in some cases death
neuromuscular junction (NMJ):
the synapse between a nerve and a muscle cell
non-depolarising neuromuscular junction (NMJ) blocker:
no stimulation or depolarisation of the muscle cell; prevents
depolarisation and stimulation by blocking the effects of acetylcholine
paralysis:
lack of muscle function
sarcomere:
functional unit of a muscle cell, composed of actin and myosin molecules arranged in layers to give the unit a striped or
striated appearance
sliding filament theory:
theory explaining muscle contraction as a reaction of actin and myosin molecules when they are freed to
react by the inactivation of troponin after calcium is allowed to enter the cell during depolarisation
Test your current knowledge of neuromuscular junction blocking agents with a PrepU Practice Quiz!
NEUROMUSCULAR JUNCTION
BLOCKING AGENTS
Non-depolarising NMJs
atracurium
cisatracurium
mivacurium
pancuronium
rocuronium
vecuronium
Depolarising NMJ
suxamethonium
