Cholinergic Rs and Drugs

Question 1

Carbachol

Answer 1

Synthetic agonist that acts on both MRs and NRs and is resistant to AChE

Question 2

Methacholine

Answer 2

Synthetic agonist that works very well only on MRs and is slightly susceptible to AChE

Question 3

3 Direct Acting Cholinomimetics

Answer 3

Nicotine
Muscarine
Pilocarpine (partial agonist)

Question 4

2 Indirect-Acting Cholinomimetics

Answer 4

Neostigmine - reversible AChE inhibitor

Sarin - nerve gas, irreversible inhibitor

Question 5

AChE Inhibitor Effect on Blood Vessels

Answer 5

Little endogenous ACh, so minimal effect

Question 6

Cholinomimetic Effect on CV System

Answer 6

In blood vessels, works on M3 smooth muscles to contract but more powerfully on M3 in endothelials, activating NO synthase so you get dilation. This causes drop in blood pressure and CNS sympathetic activation so that will counter the effects on the heart with unpredictable results

Question 7

3 MRs in Brain

Answer 7

1, 4, 5

Question 8

M2 Location/Function

Answer 8

Decrease pacemaker, conduction velocity, and contractility of heart

Question 9

M3 Location/Function

Answer 9

Vascular endothelium increases NO release and is also in glands

Question 10

Effects of Pilocarpine/Bethanechol

Answer 10

Muscarinic Cholinergic Agonists non selective forall MR subtypes so you get decreased HR from M2 and increased NO from M3 so bradycardia and hypotension

Question 11

6 Effects of Muscarine

Answer 11

M2 bradycardia, and m3 Bronchoconstriction, GI motility, pupil constriction, sweating, and salivation

Question 12

Use of Topical Pilocarpine

Answer 12

Preferred treatment of glaucoma for miosis and open canal of Schlemm

Question 13

Paradoxical Effect of Pilocarpine

Answer 13

Might cause hypertension and tachycardia, due to possible post gang symp neurons and adrenal medulla w/ M1

Question 14

2 System Inhibition of Cholinergic Agonists

Answer 14

May act on MRs at nerve terminals, inhibiting NT release from both systems

Question 15

Atropine

Answer 15

MR inhibitor, so you get blockage of vagal tone and tachycardia

Question 16

CNS Use of CholinoR Blocking Drugs

Answer 16

Some Parkinson’s patients, reduces tremors

Question 17

Scopolamine

Answer 17

CholinoR blocker for motion sickness suppresses emesis, but also causes sedation, dry mouth, and amnesia after surgery

Question 18

Eye Function of Atropine

Answer 18

Used to cause long term mydriasis (opening of pupil) for examination, but don’t use if testing for glaucoma bc need to see w/out dilation first

Question 19

2 Uses for Neostigmine

Answer 19

Indiect cholinomimetic, so used for myasthenia gravis and urinary/GI retention

Question 20

Benzatropine

Answer 20

CholinoR blocker w/ tertiary amine, so uncharged, so can cross BBB and treat parkinson’s

Question 21

Ipratropium

Answer 21

CholinoR blocker w/ quaternary amine, so stays in periphery and blocks MRs in vessels so inhaled for asthma