Chapter 19: Drugs That Block Nicotinic Cholinergic Transmission Flashcards
Nueromuscular drugs mechanism of action
- prevent ACh for activating nicotinic receptors on skeletal muscles, which results in muscle relaxation
Neuromuscular drugs cannot cross
- the blood brain barrier
- placenta
polarization
positive changes cover the outer surface of the mebrane; negative charges cover the inner membrane
depolarization
- postive changes move from the outside to inside
- in response to the binding of ACh to the nicotinic receptors
repolarization
- positively charged ions are pumped out of the cell so that the original resting membrane state is restored
- follows unbinding of ACh from endplate of nicotinic receptors
competitive (nonpolarizing) neuromuscular blockers
- do not depolarize the motor endplate
all neuromuscular blocking agents contain at least one
quaternary nitrogen atom
nondepolarizing neuromuscular blockers mechanism of action
- competes with ACH for nicotonic receptors
- blocks receptor activation of acetlcholine
competetive neuromuscular blockers pharmacologic effects
- muscle relaxation: flaccid paralysis
- hypotension
- no effect on the CNS
when a competitive neuromuscular blocker is administered peak effects persist
20-45 mins and then decline
recovery for a cometitive neuromuscular blocker takes
1 hour
competetive neuromuscular blocker effect
rapid onset of paralysis
Competetive neuromuscular blocker therapeutic uses
muscle relaxation during surgery, mechanical ventilation, endotracheal intubation
Competetive neuromuscular blockers adverse effects
- respitory arrest
- hypotension
- atracurium
Pancuronium is used for
muscle relaxation during general anesthesia, itubation, and mechanical ventelation