Drugs Week 4 Flashcards
alpha-bungarotoxin
blocks nicotinic ion channel causing paralysis. from krait or cobra venom
Neostigmine, Pyridostigmine
MOA - Blocks acetylcholinesterases thus prolonging the action of Ach in synaptic cleft. Longer acting than edrophinium.
Quatrenary ammonium - perenteral is best. Pyridostigmine is better orally absorbed. Neo is hospital only.
Uses - Myasthenia Gravis, Pyridostigmine used in war prophylacticly vs. nerve gas. Can be used post-op.
Side effects - SLUDGE Salivation, Lacrimation, Urination, Diarrhea, GI problems, emesis
Edrophinium
Anticholinesterase short acting to diagnosis Mysathenia gravis vs cholinergic crisis.
d-tubocurarine, mivacurium
Competitive blocker or Nicotininc receptor. Jaws>eyes>limbs>diaphram fail to contract; Mivacurium is shorter acting
anticholinesterases reverse block. Epi and NE a little.
Enhanced by ether, halogenated anasthetics, streptomycin, tetracycline.
Toxic effects - apnea, histamine release, cardiovascular collapse.
Metabolized by kidneys - can use atracurium which is shorter acting and not metabolized by kidneys
Succinylcholine
MOA: Depolarization of end plate of muscle. Chronic Na+ influx causes depolariazation; fasciculations precede flaccid paralysis.
Uses- w/ anasthetics for muscle paralysis; Used often for tracheal intubation. Prevention of seizures in electroshock therapy; nerve root pain vs muscle spasm impinging on nerve
Chest and abdomen most sensitive; anticholinesterases augment block.
Adverse effects - Malignant hyperthermia, apnea, histamine release, cardiovascular collapse. Can cause bronchoconstriction. Don’t use in burn patients
Dantrolene
MOA: Calcium antagonist. Nerve will fire, but muscle will not.
Uses: treatment for malignant hyperthermia.
Botulinum toxin (BOTOX)
MOA - prevents Ach release by cleaving proteins necessary for ach exocytosis. Flaccid paralysis
Last about 3 months
Uses: Muscle spasms, suppress sweating.
*most potent(lethal) toxin known. Possible bioterrorism toxin
