neuromuscular drugs Flashcards
physiology
1) long somatic nerves connecting spinal cord to muscle cells
2) Ach as primary NT
3) nicotinic cholinergic receptors
4) blocking it means loss of AP and loss of muscle contraction
drug property summary
1) pay attention to onset and duration
- onset is very important if you are trying to intubate
d-tubocurarine
1) prototype for many drugs
2) causes hypotnesion and mast cell histamine release
pancuronium
1) developed in 1960s from malouetia bequaertiana
2) moderate increase in HR but not histamine release, no ganglion blockage
3) excreted by kidney with minimal hepatic metabolism
vecuronium
1) very little vagolytic histaminic or ganglionic activity
2) duration of activity unpredictable in patients with renal or hepatic insufficiency
3) used for executions here in america
actracurium
1) removed by hoffman elimination so unaffected by renal or hepatic impairment
2) causes histamine release
3) cis-atracurium has no histamine release :)
mivacurium
1) fast onset
2) induces histamine release
3) no cardiac effects
4) elimination by plasma cholinesterases
rocuronium
1) developed for rapid onset as speed of onset related to potency
2) less potent, faster onset (1.5-3 min)
3) no histamine released, but primarily hepatic excretion
drug interactions
1) enhance neuromuscular blocking action of some inhalation anesthetics
2) drugs that inhibit presynaptic ACh release and may potentiate effects of NMJ blocking drugs
reversal agents
1) sugammadex
- inhibit aminosteroidal curonium drugs, reverses block without systemic cholinesterase inhibition
2) effects revered by acetylcholinesterase inhibitor such as neostigmine
depolarizing drugs
1) succinylcholine does what Ach does but stays there
2) persistent stimulation and depolarization of muscle
3) maintains an open state of ion channel
4) not antagonized by acetylcholinesterase
