Modulation of the Parasympathetic System and NMJ

Question 1

Direct acting cholinomimetics

Answer 1

acetylcholine, bethanechol, carbachol, cevimeline, nicotine, pilocarpine, varenicline

Question 2

Short acting anticholinesterase

Answer 2

edrophonium

Question 3

Intermediate acting anticholinesterase

Answer 3

donepezil, galantamine, neostigmine, physostigmine, pyridostigmine, rivastigmine

Question 4

Long acting anti cholinesterase

Answer 4

echothiophate, malathion, parathion, sarin

Question 5

Reactivation of acetylcholinesterase

Answer 5

pralidoxime

Question 6

Cholinoceptor blocking drugs

Answer 6

atropine, cyclopentolate, dicyclomine, homatropine, ipratropium, oxybutynin, scopolamine, tiotropium, tropicamide

Question 7

Which neurotransmitter is used at the presynaptic terminal of para and sympathetic systems?

Answer 7

acetylcholine

Question 8

What receptor is found at the post synaptic terminal of both para and sympathetic systems?

Answer 8

nicotinic

Question 9

Which neurotransmitter is found at the parasympathetic effector cell?

Answer 9

acetylcholine

Question 10

Which neurotransmitter is found at the sympathetic effector cell?

Answer 10

norepinephrine

Question 11

Which receptor is found at the parasympathetic effector organ?

Answer 11

muscarinic

Question 12

Which receptor is found at the sympathetic effector organ?

Answer 12

adrenergic

Question 13

What do cholinesterase inhibitors do?

Answer 13

inhibit the hydrolysis of endogenous acetylcholine thereby increasing the availability of naturally occurring ACh in the synapse

Question 14

All cholinergic agonists are metabolized by cholinesterase in what three places?

Answer 14

at the receptor, in the blood, and in the liver

Question 15

ACh, Carbachol, and Bethanechol pharmokinetics

Answer 15

not lipid soluble/highly charged, often have to inject it where you want it, ACh is rapidly broken down while the other two have a longer duration

Question 16

Pilocarpine, nicotine, and muscarine pharmokinetics

Answer 16

readily absorbed from most sites of administration, excreted by kidney

Question 17

Which direct cholinomimetic is not seen clinically because of toxicity and crossing the BBB?

Answer 17

muscarine

Question 18

What receptor is on the presynaptic nerve terminal of para and sympathetic systems?

Answer 18

muscarinic receptor, activation cause inhibition of neurotransmitter release

Question 19

T/F muscarinic receptors are g protein coupled and produce 2nd messenger cascade that directly affects organ function

Answer 19

true

Question 20

T/F nicotinic receptors are ion channel and activation produces depolarization of the nerve cell or NMJ

Answer 20

true

Question 21

What is the result of prolonged agonist binding to the nicotinic post ganglion neuron?

Answer 21

desensitization/depolarizing blockade, prevents recovery

Question 22

What is the muscarinic effect on the eye?

Answer 22

miosis (contraction of sphincter), accommodation, opening of TM (lower IOP)

Question 23

What is the muscarinic effect on the heart?

Answer 23

decrease in heart rate (hyperpolarization of SA and AV node)

Question 24

What is the muscarinic effect on blood vessels?

Answer 24

indirect vasodilation and decrease in peripheral resistance (in atherosclerosis will cause vasoconstriction)

Question 25

What is the muscarinic effect on the respiratory system?

Answer 25

contraction of bronchial smooth muscle aka broncho-constriction and increased mucous secretion

Question 26

What is the muscarinic effect on the GI tract?

Answer 26

increase smooth muscle motility and relax most sphincters, stimulate salivary and gastric glands to secrete

Question 27

What is the muscarinic effect of the urinary tract?

Answer 27

stimulate detrusor and relax trigone and sphincter aka promote urination

Question 28

What is the muscarinic effect on other glands?

Answer 28

SECRETION sweat, lacrimal, nasopharyngeal

Question 29

T/F activation of nicotinic receptors often resembles simultaneous discharge on both para and sympathetic system

Answer 29

true be careful of drug side effects

Question 30

Activation of nicotinic receptors in autonomic ganglia cause simultaneous...

Answer 30

sympathomimetic cardiovascular activity (increase HR and BP) AND parasympathomimetic GI and Urinary activity (nausea, vomiting, diarrhea, and urination)

Question 31

What is the nicotinic effect at the NMJ?

Answer 31

depolarization followed by depolarization blockage aka desensitization

Question 32

T/F most indirect acting cholinomimetics are simple alcohols or esters

Answer 32

true

Question 33

T/F derivatives of phosphoric acid (organophosphates) have the shortest duration of action

Answer 33

false

Question 34

What is the administration of indirect cholinomimetics?

Answer 34

any including IV

Question 35

Where are organophosphates absorbed from?

Answer 35

skin, lung, gut, and conj -- dangerous to humans

Question 36

Which intermediate indirect drug is well absorbed from all sites and can be used topically in the eye?

Answer 36

physostigmine

Question 37

T/F organophosphates are distributed to the CNS

Answer 37

true, CNS toxicity is common

Question 38

Which organophosphate does not cross the CNS?

Answer 38

echothiophate

Question 39

Why is edrophonium short acting?

Answer 39

forms a reversible bond with the enzyme but is not actually a substrate for ACh-esterase

Question 40

What is the MOA of intermediate acting drugs?

Answer 40

neostigmine, physostigmine, and pyridostigmine are resistant to part of the enzyme action so it takes longer

Question 41

What is the MOA of echothiophate, malathion, parathion, and sarin?

Answer 41

forms phosphorylated enzyme complex that strengthens the bond with the drug aka completely deactivates ACh-ase

Question 42

What effect do low concentrations of indirect acting drugs have?

Answer 42

alerting response

Question 43

What effect do high concentrations of indirect acting drugs have?

Answer 43

convulsions

Question 44

What happens to the cardiovascular system when indirect acting drugs are used?

Answer 44

increased activity in both sympathetic and parasympathetic ganglia as well as increased activity at muscarinic receptors

Question 45

Which system dominates the cardiovascular response to indirect acting cholinergic agonists?

Answer 45

parasympathetic because of direct muscarinic innervation aka decreased HR and decreased cardiac output

Question 46

What is the indirect cholinergic agonist effect at the NMF?

Answer 46

prolong and intensify actions of acetylcholine, strengthen muscle contraction=helpful in myasthenia gravis

Question 47

T/F the NMJ can be desensitized by high or prolonged concentrations

Answer 47

true

Question 48

Which cholinomimetics can treat glaucoma?

Answer 48

carbachol, pilocarpine, echothiophate(obsolete)

Question 49

Which cholinomimetic treats urinary retention?

Answer 49

bethanechol or neostigmine

Question 50

Which cholinomimetic treats dry mouth?

Answer 50

cevimeline, pilocarpine

Question 51

Which cholinomimetics treat myasthenia gravis?

Answer 51

edrophonium (diagnosis) and pyridostigmine maybe neostigmine

Question 52

T/F cholinomimetics may help treat alzheimer's?

Answer 52

true (donepezil, galantamine, rivastigmine)

Question 53

How do cholinomimetics work in the eye?

Answer 53

cause contraction of the ciliary body +miosis to increase aqueous outflow

Question 54

What cholinomimetic can reverse neuromuscular blockage produces during surgical anesthesia?

Answer 54

neostigmine and edrophonium

Question 55

What are adverse effects of direct acting cholinomimetics?

Answer 55

nausea, vomiting and diarrhea (increase GI activity) urinary urgency, salivation and sweating (increase secretions) flushing of skin from vasodilation and bronchial constriction

Question 56

What are adverse effects of cholinesterase inhibitors?

Answer 56

same as direct + muscle weakness (NMJ), convulsions (CNS) and respiratory failure

Question 57

What are symptoms of organophosphate poisoning?

Answer 57

same as cholinesterase inhibitors

Question 58

What are the effects of cholinergic blockers (muscarinic antagonists)?

Answer 58

interrupt parasympathetic nerve impulses and prevent ACh from stimulating cholinergic receptors

Question 59

T/F Cholinergic blockers can be divided into muscarinic and nicotinic subgroups

Answer 59

true

Question 60

What is an example of a naturally occurring muscarinic antagonists?

Answer 60

atropine, derived from nightshade plant

Question 61

What is an example of a synthetic muscarinic antagonist?

Answer 61

tropicamide

Question 62

What is the absorption of cholinergic blockers?

Answer 62

most are well absorbed in the gut, conj and across skin

Question 63

What is the distribution of cholinergic blockers?

Answer 63

widely distributed with CNS penetration

Question 64

Where are muscarinic antagonists eliminated?

Answer 64

kidney

Question 65

What is the MOA of cholinergic blockers?

Answer 65

block acetylcholine action at muscarinic receptors, moderately selective for receptor subtypes

Question 66

Is atropine selective or nonselective?

Answer 66

nonselective, useful in treating cholinomimetic toxicity like from organophosphates

Question 67

Which muscarinic antagonist has minimal CNS effects and which has marked effects?

Answer 67

minimal atropine, marked scopolamine

Question 68

What are scopolamine's side effects and why does it have them?

Answer 68

drowsiness and amnesia, also reversal of vestibular disturbances, side effect because it crosses the BBB

Question 69

What are cholinergic blocker effects on the cardiovascular system?

Answer 69

increased HR

Question 70

What are cholinergic blocker effects on the eye?

Answer 70

mydriasis from blocking muscarinic activation of pupillary constrictor muscle allowing unopposed sympathetic dilator activity--- also cycloplegia from weakening ciliary muscle-- and reduction in lacrimal secretion

Question 71

What are muscarinic antagonist effects on the respiratory system?

Answer 71

bronchodilation and decrease in secretions

Question 72

What are muscarinic antagonist effects on GI tract?

Answer 72

decreased salivation and stomach acid, decreased smooth muscle tone and less propulsive movements

Question 73

What are cholinergic blocker effects on the urinary tract?

Answer 73

relax bladder smooth muscle which slows voiding

Question 74

What do cholinergic blockers do to sweat glands?

Answer 74

reduces sweating and can induce fever in younger patients

Question 75

What CNS disorders are antimuscarinic drugs used for?

Answer 75

parkinsons and treatment of motion sickness

Question 76

What antimuscarinic drugs are used for accurate refraction?

Answer 76

cyclopentolate or homatropine

Question 77

What antimuscarinic drugs are used for dilated fundus exam?

Answer 77

tropicamide or cyclopentolate

Question 78

What antimuscarinic drugs are used for uveitis and prevention of synechia?

Answer 78

homatropine or cyclopentolate

Question 79

What are characteristics of iris synechia?

Answer 79

irregular pupil and increased IOP possible

Question 80

What is the duration of eye drop dilation effects?

Answer 80

atropine 7-10 days, homatropine 1-3 days, cyclopentolate 1 day, tropicamide 6 hours

Question 81

What antimuscarinic drugs are used as pre-anesthesis to prevent airway secretions?

Answer 81

atropine or scopolamine

Question 82

What antimuscarinic drugs treat COPD and asthma because of bronchodilation?

Answer 82

ipratropium or tiotropium

Question 83

What antimuscarinic drugs treat urinary urgency or bladder spasm?

Answer 83

oxybutynin

Question 84

T/F antimuscarinic drugs treat bradycardia and some arrhythmias

Answer 84

true

Question 85

What is cholinergic poisoning?

Answer 85

long acting indirect poisoning

Question 86

What drug has an antimuscarinic effect used to treat cholinergic poisoning?

Answer 86

atropine because its nonspecific, multiple doses required

Question 87

What cholinesterase regenerator can treat cholinergic poisoning if used rapidly?

Answer 87

pralidoxime because it can regenerate phosphorylated enzyme

Question 88

What are adverse effects of antimuscarinic drugs?

Answer 88

mydriasis and light sensitivity, decreased accommodation, dry mouth, tachycardia, flushed skin, agitation, delirium, elevated body temp

Question 89

T/F Cholinoreceptor agonists cause SLUD

Answer 89

true, salivation, lacrimation, urination, diarrhea

Question 90

What are the cholinoreceptor antagonists? (opposite effect of SLUD)

Answer 90

dry mouth, dry eyes, urinary retention, constipation