Ganglionic and NM Blockers

Question 1

Used as an adjunct to nicotine patch against nicotine craving

Answer 1

Mecamylamine

Question 2

Trimethaphan uses

Answer 2

Hypertensive emergencies, dissecting aortic aneurysms, autonomic dysreflexia

Question 3

Adverse effects of ganglionic blockers

Answer 3

CNS:  tremor, chorieform mvmts
Eye:  blurred vision bc of cycloplegia
CV:  decr tone in vessels, leading to hypotension; tachycardia 
GI:  constipation and GI dysmotility
Urinary retention, sexual dysfxn

Question 4

Nondepolarizing neuromuscular blockers and their MOA

Answer 4

Pancuronium, atracurium, mivacurium
Bind to Ach receptor, blocking Ach from binding. In large amts, they decr sensitivity to cholinesterase inhibitors, further decr Ach effects on postsynaptic neuron

Question 5

Depolarizing neuromuscular blockers and their MOA

Answer 5

Succinylcholine
Bind to channel while it is open, keeping channel open and messing up the membrane potential. Therefore, that receptor will not fire with a normal stimulus

Question 6

Would you have to give more or less of a NM nondepolarizing blocking agent to a pt w/ myasthenia gravis?

Answer 6

Less bc these pts already have many Ach receptors blocked by autoantibodies against the Ach receptors

Question 7

Non-depolarizing blockers have adverse drug interactions w/ what type of drugs?

Answer 7

1. Inhaled anesthetics (remember that anesthetics act on Na channels as well, so you get a double whammy on nicotinic Na receptors)
2. Aminoglycosides such as gentamicin and streptomycin (I’m not exactly sure why)
3. Tetracyclines (again, I have no idea why; if someone knows, please enlighten us)
4. Ca channel blockers (decr amt of Ach released from the presynaptic neuron, resulting in less Ach available to bind to an already low # of available Ach receptors that are not bound by non-depolarizing blockers)

Question 8

When would you use cisatracurium?

Answer 8

In a critically ill pt who needs a paralytic agent (i.e. for surgery or intubation) and who has impaired renal and hepatic fxn. This is bc of the way that cisatracurium is metabolized.

Question 9

Which of the following intermediate-acting non-depolarizing blockers would have significant effects on CV and respiratory systems in high doses? (and 10 points to Gryffindor if you know why)

A. Atracurium
B. Cisatracurium
C. Rocurium
D. Vecuronium

Answer 9

A. Atricurium bc it causes release of histamine, which causes bronchoconstriction and vasodilation.

Question 10

What drug has the most badass name that we learned so far?

Answer 10

Sugammadex

Question 11

What does sugammadex do?

Answer 11

Reverses the action of steroid NMJ blockers (vecuronium, rocuronium, pancuronium) by forming water-soluble complexes with these drugs, allowing them to be easily removed from the NMJ and excreted.

Question 12

What is the typical DOC for paralysis so that you can intubate someone?

Answer 12

Succinylcholine

Question 13

Why do you have to be careful w/ giving succinylcholine?

Answer 13

Its effects are not reversible and there is no antidote for it.

Question 14

What are some contraindications and adverse effects of succinylcholine?

Answer 14

Contraindications are pts w/ unhealed skeletal muscle injury (it is opening up nicotinic channels, causing muscle contraction, which you wouldn’t want in a healing muscle).

Adverse effects include cardiac arrest (get a ton of K+ release when succinylcholine binds and opens channel, causing hyperkalemia, which may mess w/ the cardiac action potential), malignant hyperthermia (sudden contraction of all skeletal muscles incr body heat), postop myalgia (due to fasciculations), incr IOP (idk why)

Question 15

Congrats! You’ve mastered all of the Neuro Pharm flash cards

Answer 15

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