Pharmacology of Neuromuscular Blocking Agents Flashcards
What is the MOA of depolarizing neuromuscular blockers?
Initially depolarize the cell, followed by persisted occupation of the receptor site that delays repolarization
What is the MOA of Dantrolene?
Direct-acting skeletal muscle relaxant – Binds to ryanodine receptor 1 and decreases intracellular calcium
What ADRs are associated with depolarizing neuromuscular blockers?
Muscle twitching, hyperkalemia, respiratory depression, increased ocular pressure, hypertension, tachycardia, arrhythmias, salivation
What is the active metabolite of succinylcholine?
Succinylmonocholine
What are the uses of Dantrolene?
Treatment of chronic muscle spasticity and malignant hyperthermia
What is the major ADR associated with Dantrolene?
Hepatotoxicity
What types of muscle fibers (slow/fast) are more susceptible to the effects of direct-acting skeletal muscle relaxants?
Fast-twitch muscle fibers
What are the steroid derivative non-depolarizing neuromuscular blockers?
Vecuronium, Rocuronium
When are non-depolarizing neuromuscular blockers contraindicated?
During overdose with depolarizing blockers - receptor sites will be blocked and OD effects will be prolonged
This drug may be administered via IV during surgery to treat malignant hyperthermia.
Dantrolene
What neuromuscular blocker is commonly used in emergency situations to facilitate intubation?
Succinylcholine
What are the two types of neuromuscular blockers?
Depolarizing & Non-depolarizing
What drug can be administered an an antidote for non-depolarizing neuromuscular blockers?
Sugammadex
What are the isoquinolone derivatives?
Tubocurarine, Cisatracurium
What are the contraindications for use of a depolarizing neuromuscular blocker?
History of malignant hyperthermia, narrow-angle glaucoma
What is the MOA of Succinylcholine?
Depolarizing neuromuscular blocker
True/False. Neuromuscular blockers penetrate the BBB.
False. They cannot penetrate the BBB, thus there is little CNS effect
How can an overdose by a non-depolarizing neuromuscular blocker be treated?
Mechanical respiration, vasopressors, cholinesterase inhibitors
What non-depolarizing neuromuscular blockers are most likely to increase histamine release?
Isoquinolone derivatives
Cholinergic drugs and corticosteroids have what effect on neuromuscular blockers?
Reduce pharmacological effectiveness
What is the MOA of direct-acting skeletal muscle relaxants?
Act directly on skeletal muscle fibers to decrease Ca2+ release
Malignant hyperthermia is a serious ADR associated with what class of neuromuscular blockers?
Depolarizing blockers
What is the MOA of non-depolarizing neuromuscular blockers?
Competitively bind to post-synaptic ACh cholinergic receptors
What type of neuromuscular blocker produces flaccid paralysis?
Non-depolarizing blockers
What are the primary uses of neuromuscular blockers?
Facilitate intubation, improve respiration with mechanical respirators
Blocking of receptors by neuromuscular blockers beings (peripherally/centrally).
Peripherally. At low doses, rapidly contracting small muscles are first blocked and moves centrally. Recovery occurs in the reverse order, starting with the diaphragm and intercostal muscles.
What is the MOA of sugammadex?
Encapsulates drug to prevent receptor binding
