Ch 18 Neuromuscular Blocking Agents Flashcards
What are the two types of drugs that cause skeletal muscle weakness and paralysis
- Nondepolarizing agent
- Depolarizing agent
Acetylcholineesterase (AchE)
Enzyme that breaks down the neurotransmitter acetylcholine ( Ach) at the synaptic cleft so that the next nerve impulse can transmit across the synaptic gap
Amnestic properties
Ability to cause total or partial loss of memory
Fasciculation
Involuntary contractions or twitching of groups of muscle fibers
What is the clinical use of neuromuscular blocking agents (NMBAS)
Intubation
Muscle relaxation during surgery
What does neurotransmitter releases in the peripheral nervous system
Neurotransmitter release acetylcholine
What breaks down the neurotransmitter -( transmits nerve conduction in skeletal muscle)
Acetylcholinesterase
What happens in depolarization of neurotransmitter junction
Skeletal muscle contraction
What are two ways to block muscle contraction
- Competitive inhibition : nondepolarizing agent
- Prolonged occupation and persistent binding: depolarizing agent
What is the mode of action for nondepolarizing agent s
Competitive inhibition of acetylcholine at muscle receptor sites
- results in paralysis
- cholinesterase inhibitors (neostigmine) can reverse blockade( reverses paralysis)
Nondepolarizing agent pharmacokinetics
Have longer duration than depolarizing agents
What is the only depolarizing agent
Succinylcholine
Shorter acting
No reversal agents
Paralysis in 60-90 seconds with a duration from 10-15 min
Don’t offer anxiety relief nor decrease consciousness
Mode of action for depolarizing agents
Causes fasciculations (twitching)
What should patient receive prior to receiving NMBA
Analgesic and sedative
