Parasympathetic Nervous System by Prof. Krouse

Question 1

What does hemicholinium inhibit?

Answer 1

Inhibit choline uptake at Na+/Choline Symporter

Question 2

How does botox work?

What is it used to treat?

Answer 2

Prevents ACh vesicle fusion

Facial muscle spasms, strabismus (abnormal alignment of the eyes), wrinkles

Question 3

Why is ACh used clinically?

Answer 3

Minor oculasr procedures for brief miosis (circulating AChE eats it up)

Question 4

Why is Bethanochol used?

What is its mechanism of action?

Why don’t you give it IV?

Answer 4

Atonic gut, urinary retention after surgical procedures

M agonist

Powerful! Cardiac Arrest!

Question 5

Why is Methacholine used? (Two reasons.)

Answer 5

To test for bronchoreactivity in case of asthma; reactivity

Diagnostic for bella donna poisoning

Question 6

What is carbachol used for?

What is its mechanism of action?

Answer 6

Glaucoma if pilocarpine is ineffective

Muscarinic agonist with some nicotinic activity

Question 7

What happens in mushroom poisoning?

Answer 7

Muscarine OD!

Question 8

Why is Pilocarpine used?

What is its mechanism of action?

How does it work?

Answer 8

Acute/Emergecy Glaucoma treatment

muscarinic agonist

Contracts ciliary muscle to relieve intraocular pressure

Question 9

What are the symptoms of muscarinic toxicity?

Answer 9

Think DUMBBELS or SLUDE

Diarrhea
Urination
Miosis
Bronchorrea (increased mucus)
Bradycardia
Emesis
Lacrimation
Salivation Sweating

Question 10

What are the symptoms of nicotinic toxicity?

Answer 10

Think MTWThF

Mydriasis
Tachycardia
Weakness (muscle paralysis)
Th - hyperthermia
Fasciculations

Question 11

When would you see muscarinic and nicotinic toxicity simultaneously?

Answer 11

Organophosphate toxicity

Question 12

Why is mydriasis and tachycardia present in nicotinic excess?

Answer 12

Overstimulation of nAChR at ganglia leads to depolarizing blockade

Question 13

What is Edrophonium?

Why is used?

Answer 13

Reversible AChE inhibitor

diagnostic of myasthenia gravis

Question 14

What is the difference between physostigmine and neostigmine? What are they both?

Answer 14

Physo - CNS action (tertiary amine); NEO - NO CNS action (quat amine with charge)

Both are reversible AChE inhibitors

Question 15

Describe myasthenia gravis.

Answer 15

Autoimmune disorder with antibodies against nAChR receptors.

Question 16

Why is neostigmine used?

Answer 16

treatment for MG; AChE inhibited 0.5-6 hrs

Question 17

Ephedronium test

Answer 17

Normal - no change in grip strength

MG - increased grip strength

Question 18

Why is pyridostigmine used? How does it work?

Answer 18

MG; reversible AChE inhibitor with longer lasting effects than neostigmine

Question 19

What is DFP?

Answer 19

organophosphate used in glaucoma treatment

Question 20

What is echothiophate?

Answer 20

Low lipid solubility irreversible AChE inhibitor

2nd line agent for glaucoma

Question 21

Nerve gases

Answer 21

irreversible AChE inhibitors

Question 22

What are Malathion and Parathion?

How do animals metabolize them?

How do humans metabolize them?

Answer 22

Insecticides which are prodrugs

S (inactive) via absorption O (active)

Back to O!

Question 23

Which is more toxic: malathion or parathion?

Answer 23

Parathion

Question 24

What’s the aging timelag for nerve gases vs. malathion?

Answer 24

sec/mins vs. 4-6 hrs.

Question 25

How does 2-PAM work?

Answer 25

Regenerates AChE after organophosphate

Question 26

Which AChE inhibitor would you use to treat atropine or TCA OD?

Answer 26

physostigmine (not neostigmine)

Question 27

What is the treatment for AChE inhibitor toxicity?

Answer 27

Atropine+2-PAM+Mechanical Respiration

Question 28

Why is physostigmine used?

Answer 28

Reverse atropine toxicity; Glaucoma treatment

Question 29

Succinylcholine

Answer 29

NMJ paralysis, depolarizing block because it's a long-acting agonist, short acting due to plasma AChE

Question 30

Tubocararine

Answer 30

NMJ paralysis, competitive blocker, flaccid paralysis, short acting

Question 31

Rocuronium/cisAtracurium

Answer 31

Fast onset, short-intermediate duration

Question 32

How does atropine work? What does it do? What are some phrases to help remember its effects?

Answer 32

Competitive mAChR antagonist mydriasis, cyclopegia, decreased GI activity, decreased secretions, relaxed lungs Mad as a hatter (delirium), red as a beet (erythematous, blind as a bat (cyclopegia), dry as a bone (decreased secretions), hot as hell (thermoregulation)

Question 33

What's the clinical use of atropine?

Answer 33

Reverse the toxic effects of physostigmine or neostigmine (reversible AChE inhibitors)

Question 34

Ipratropium is used to treat Mechanism of action?

Answer 34

Asthma, COPD Comptetivie muscarinic receptor antagonist

Question 35

Tiotropium is used to treat? Mechanism of acpiloction?

Answer 35

Ashtma, COPD competitive muscarinic receptor antagonist

Question 36

Benztropine is used to treat? Mechanism of action?

Answer 36

drug-induced Parkinsonian symptoms competitive muscarinic receptor antagonist

Question 37

Scopolamine is used to treat? Mechanism of action?

Answer 37

Motion sickness, diarrhea, decreased secretions competitive muscarinic receptor antagonist

Question 38

Propantheline is used to treat Mechanism of action?

Answer 38

GI disorders (e.g. mild diarrhea) competitive muscarinic receptor antagonist

Question 39

A patients presents with iritis. What do you have her?

Answer 39

atropine

Question 40

What receptors are in the ciliary body? Which division of the ANS controls it?

Answer 40

muscarinic, parasympathetic

Question 41

How do you treat open-angle glaucoma?

Answer 41

beta blockers

Question 42

How do you treat closed-angle glaucoma?

Answer 42

pilocarpine or surgery (punch holes into iris)

Question 43

How does you treat chronic glaucoma?

Answer 43

timolol or latanoprost

Question 44

How do beta blockers work on glaucoma?

Answer 44

Inhibiting the secretion of aqueous humor

Question 45

How do the prostaglandins work on glaucoma? What are their side effects?

Answer 45

Increasing outflow for another route darken pupil, red eyes (inflammation)

Question 46

Acetazolamide

Answer 46

Glaucoma treatment via decreased secretion

Question 47

Nicotine

Answer 47

Insecticide, cigarettes nicotinic receptor agonist

Question 48

Why are Trimethapan and Mecamyline used? What is their mechanism of action?

Answer 48

decreased BP during surgery (trimethapan), last resort in chronic hypertension because of its side effects (mecamyline) Competitive nicotinic receptor antagonist @ the ganglia