Cholinergics

Question 1

Cholinergic agonist
Direct acting
-Rarely used clinically, except topically on eye because it will also stimulate nicotinic receptors
-Also has short half-life

Answer 1

acetylcholine

Question 2

Cholinergic agonist
Direct acting
-Not used clinically
-In some poisonous mushrooms, however many toxins may be present
-How muscarinic receptors were discovered

Answer 2

Muscarine

Question 3

Cholinergic agonist
Direct acting
-Topical opthalmic use–> pupil constriction and decrease in intraocular pressure during glaucoma
-Can also be used systemically to promote salivation

Answer 3

Pilocarpine

Question 4

Cholinergic agonist
Direct acting
-Some selectivity for M3
–> affects bladder more than heart, especially at lower doses –> causes contraction of detruser m, and relaxation of trigone and sphincter
–> can treat urine retention if no obstruction present
-Some GI effects

Answer 4

Bethanechol

Question 5

Cholinergic agonist
Acetylcholinesterase inhibitor
-Covalent inhibitor
-Topically for glaucoma, treat smooth muscle atony in GI or urinary, treat myasthenia gravis, counter anticholinergic poisoning

Answer 5

Physostigmine and neostigmine

-neostigmine doesn’t cross blood brain barrier

Question 6

Cholinergic antagonist
Direct acting competitive
-Can enter CNS 
		-Excitation followed by depression 
-Some rabbits have enzyme to break down atropine--> much shorter half-life

Answer 6

Atropine and scopolamine

Question 7

Cholinergic antagonist
Direct acting competitive
-Used topically in eye to dilate pupil
-Shorter duration of action

Answer 7

Tropicamide

Question 8

Cholinergic antagonist
Direct acting competitive
-Inhalent–> decreased respiratory secretion and bronchoconstriction

Answer 8

Ipratropium

Question 9

Cholinergic antagonist
Direct acting competitive
-Doesn’t enter CNS
-Used to prevent bradycardia under anesthesia

Answer 9

Glycopyrrolate

Question 10

Cholinergic antagonist
Direct acting competitive
-Decreased detruser contraction, increased sphincter contraction
-Used to treat incontinence due to detruser instability

Answer 10

Propantheline