Neuromuscular Relaxants Flashcards Preview

Pharmacology > Neuromuscular Relaxants > Flashcards

Flashcards in Neuromuscular Relaxants Deck (53)
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1
Q

Where do neuromuscular relaxants act?

A

Neuromuscular relaxants selectively block the nicotinic receptors at the neuromuscular junction

2
Q

How do Nm receptors trigger muscle contraction?

A

2 ACh are released and bind Nm leading to EPP which will summate into an AP that will propagate down to the T tubules and activate L-type Ca2+ channels which leads to contraction

3
Q

How do non-depolarizing drugs function?

A

They are competitive antagonists of Nm

4
Q

How do depolarizing drugs function?

A

They cause prolonged Nm activation and depolarization

5
Q

How can non-depolarizing drugs be overcome?

A

Excess ACh

6
Q

Do non-depolarizing cross the BBB?

A

No

7
Q

Where is the receptor reserve the highest in?

A

Respiratory > Large Limbs > Fine muscles

8
Q

What is the onset of the depolarizing drugs like?

A

They have a more rapid onset that is metabolized by plasma cholinesterase

9
Q

What is the antidote for non-depolarizing drugs?

A

Cholinesterase inhibitors

10
Q

What is the antidote for depolarizing drugs?

A

Phase 1 - Time

Phase 2 - Cholinesterase Inhibitors

11
Q

What are the side effects of non-depolarizing drugs?

A

Non analgesic
Apnea
Increased HR due to muscarinic block

12
Q

What are the side effects of depolarizing drugs?

A
Not analgesic
Apnea
Muscle pain fasciculations
HTN
Hyperkalemia
13
Q

Why should Phase 2 block from depolarizing drugs be avoided?

A

Phase 2 causes desensitization where it re-polarizes but it cannot be depolarized again by ACh

14
Q

What non-depolarizing agent is best for long procedures?

A

Pancuronium

15
Q

What non-depolarizing agent is best for short procedures?

A

Mivacurium

16
Q

What non-depolarizing agent is best for renal failure patients?

A

Rocuronium

17
Q

What non-depolarizing agent is best for liver failure patients?

A

Pancuronium

18
Q

What non-depolarizing agent is best for medium length procedures?

A

Vecuronium

19
Q

What is the stretch reflex arc?

A

1a afferents excite and cutaneous internuncial afferent inhibit extrafusal efferents that stimulate skeletal muscle contraction

20
Q

What is the cause of muscle spasticity?

A

It is due to the release from inhibition of supra spinal control with heightened alpha and gamma systems and increased activation of facilitory paths

21
Q

Clonus

A

Reduced ability to lower calcium between stimulations due to increased frequency of stimulation leads to incomplete relaxation

22
Q

What are the curare drugs?

A

Non-depolarizing agents

23
Q

What are the spasmolytic drugs?

A

Baclofen
Diazepam
Tizanidine
Dantrolene

24
Q

Succinylcholine effect

A

Depolarization blockade of muscle nicotinic receptors

25
Q

Succinylcholine indication

A

Endotracheal intubation

Electro-convulsive shock therapy

26
Q

Succinylcholine elimination

A

Plasma cholinesterase

27
Q

Pancuronium effect

A

Non-depolarizing blockade of muscle nicotinic receptors

28
Q

Pancuronium elimination

A

Renal excretion

29
Q

Pancuronium indication

A

Adjuvant in surgical anesthesia, sp. abdominal wall relaxation & orthopedic procedures

30
Q

D-tubocurarine use

A

Prototype - only used in lethal injection. No clinical use.

31
Q

Rocuronium effect

A

Non-depolarizing blockade of muscle nicotinic receptors

32
Q

Rocuronium elimination

A

Liver

33
Q

Rocuronium indication

A

Intubation, muscle relaxation during surgery or ventilation

34
Q

Mivacurium effect

A

Non-depolarizing blockade of muscle nicotinic receptors

35
Q

Mivacurium elimination

A

Plasma cholinesterase

36
Q

Mivacurium indication

A

Intubation, muscle relaxation during surgery or ventilation in pts w/ renal failure

37
Q

Vecuronium effect

A

Non-depolarizing blockade of muscle nicotinic receptors

38
Q

Vecuronium elimination

A

Liver metabolism and clearance, renal elimination

39
Q

Vecuronium indication

A

Adjuvant in surgical anesthesia, sp. abdominal wall relaxation & orthopedic procedures

40
Q

Baclofen target and effect

A

GABAb agonist

Reduces calcium influx, and therefore reduces the release of excitatory transmitters and substance P in spinal cord

41
Q

Baclofen indication

A

Spinal Spasticity

Multiple Sclerosis

42
Q

Baclofen toxicity

A

Drowsiness

43
Q

Diazepam/Clonezapam target and effect

A

Facilitate GABA mediated pre- synaptic inhibition

Benzodiazepine receptor agonist

44
Q

Diazepam/Clonezapam indication

A

Spinal Spasticity

Multiple Sclerosis

45
Q

Diazepam/Clonezapam toxicity

A

Sedation and drowsiness

46
Q

What is the function of GABA?

A

Reduces neuronal excitability

47
Q

Tizanidine target and effect

A

Alpha2-adrenergic agonist

48
Q

Tizanidine indication

A

Spinal Spasticity

Multiple Sclerosis

49
Q

Tizanidine toxicity

A

Drowsiness

Hypotension

50
Q

Dantrolene effect

A

Blocks calcium release from sarcoplasmic reticulum in muscle, thus interfering with excitation-contraction in the muscle fiber

51
Q

Dantrolene indication

A

Spasticity

Malignant Hyperthermia

52
Q

Dantrolene toxicity

A

Muscle Weakness

Sedation

53
Q

What is the important alternative use of dantrolene?

A

Treating malignant hyperthermia as it can block ryanodine receptors

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