Cholinergic Drugs

Question 1

what are esters of choline

Answer 1

direct acting choline agonists that are quaternary ammonium compounds that differ by their susceptibility to hydrolysis by cholinesterases

Question 2

name the choline esters

Answer 2

acetycholine, carbachol, bethanechol, methacholine

Question 3

which of the choline esters are more resistant to hydrolysis by cholinesterases

Answer 3

carbachol, bethanechol, methacholine

Question 4

uses of acetycholine

Answer 4

for rapid miosis after delivery of lens in cataract surgery, in penetrating keratoplasy, iridectomy, and other anterior segment surgery

Question 5

what receptor does bethanechol work on

Answer 5

it has strong muscarinic activity and little to no nicotinic activity

Question 6

uses of bethanechol

Answer 6

acute post op and postpartum urinary retention and neurogenic atony of the urinary bladder for retention

Question 7

adverse effects of bethanechol

Answer 7

generalized cholinergic stimulation: sweating, salivation, flushing, low BP, nausea, abdominal pain, diarrhea, bronchospasm

Question 8

receptors that carbachol works on

Answer 8

both muscarinic and nicotinic

Question 9

uses of carbachol

Answer 9

• miosis during surgery

- reduces intra-ocular pressure after cataract surgery (glaucoma)

Question 10

receptor that methacholine works on

Answer 10

primarily muscarinic agonist with slight nicotonic action

Question 11

uses of methacholine

Answer 11

diagnosis of bronchial airway hyper-reactivity in those who are not apparent asthmatics

Question 12

classify all the choline esters in term of agonists to what receptors

Answer 12

methacholine, bethanechol, acetylcholine, and carbachol are all muscarinic agonists

exception of carbachol which is also a nicotinic agonist

Question 13

what are the natural alkaloids and what receptors they work on

Answer 13

muscarine, arecoline, pilocarpine –> all muscarinic agonist with exception to arecoline which is also a nicotinic agonist

Question 14

of all the natural alkaloids which is the only used clinically and what is its use

Answer 14

pilocarpine - second line agent for open angle glaucoma and for management of acute angle-closure glaucoma

Question 15

adverse effects of pilocarpine

Answer 15

• enter brain and cause CNS disturbance

- sweating and salivation

Question 16

use of nicotine

Answer 16

used for the cessation of smoking

Question 17

what is the biggest difference between the indirect cholinergic agonists edrophonium, carbamates, and organophosphates

Answer 17

how long their effect last
in order of increasing effect time
edrophonium, carbamates, then organophosphates

they are all cholinesterase inhibitors hence prolonging the effect of acetylcholine

Question 18

use of edrophonium

Answer 18

diagnosis of myasthenia gravis; used to reverse the neuromuscular block produced by non depolarizing blockers

Question 19

what isn’t edrophonium used for tx of said disease and rather just for diagnosis

Answer 19

it is very short acting

Question 20

what are the carbamates

Answer 20

neostigmine, physostigmine, pyridostigmine

Question 21

what is the use of physostigmine

Answer 21

tx for overdose on anti cholinergic drugs

Question 22

what is so special about physostigmine and what type of pt do you not give this drug to

Answer 22

it can cross the BBB

do not give to those who overdose on TCA because it can aggravate depression of cardiac conduction

Question 23

adverse effects of physostigmine

Answer 23

• crosses CNS and can lead to convulsion if high doses are used
• bradycardia
• at NMJ, huge collection of acetycholine can lead to paralysis of skeletal muscle

Question 24

uses of neostigmine

Answer 24

• could be used for myasthenia gravis
• reversal of effects of non depolarizing neuromuscular blockers after surgery (most common use)
• prevention and tx of post op distention and urinary retention

Question 25

adverse effects of neostigmine

Answer 25

salivation, flushing, low BP, nausea, vomiting, diarrhea, bronchospasm

Question 26

uses of pyridostigmine

Answer 26

treatment of myasthenia gravis (most common use)

Question 27

what is echothiophate used for

Answer 27

chronic open angle glaucoma, subacute or chronic angle closure glaucoma, or where surgery is contraindicated basically used for glaucoma

Question 28

what are malathion and parathion

Answer 28

they are insecticides and are dangerous acetylcholinesterase inhibitors

Question 29

what are tabun, sarin, and soman

Answer 29

potent synthetic toxic agent acetylcholinesterase inhibitors

Question 30

acetylcholinesterases approved for treatment of alzheimers

Answer 30

donepezil, rivastigmine, and galantamine

Question 31

drug used for organophosphate insecticide poisoning because it is a cholinesterase regenerator

Answer 31

pralidoxime

Question 32

muscarinic receptor antagonist

Answer 32

atropine, scopolamine

Question 33

actions of atropine

Answer 33

eyes - mydriasis, increase intraocular pressure dangerously in those with glaucoma GI - reduces motility Urinary - decreases hypermotility of bladder cardiovascular - blockade of M2 receptors and tachycardia salivary, sweat, and lacrimal glands blocked increase in body temp since sweat glands are blocked

Question 34

what is atropine used for

Answer 34

- antisialogogue (reduce saliva production) - increase heart rate or decrease AV block - antidote for amanita muscaria - antidote for overdose on cholinergic drugs - alleviate side effects of muscarinic side effects of anticholinesterase drugs

Question 35

adverse effects of atropine

Answer 35

dry mouth, blurred vision, sandy eyes (dry eyes), tachycardia, restlessness, confusion, hallucinations, delirium, depression, exacerbate an attack of glaucoma

Question 36

difference between atropine and scopolamine

Answer 36

scopolamine has greater action in CNS and longer duration of effects

Question 37

uses of scopolamine

Answer 37

mydriasis and cycloplegia (for diagnostic procedures) prevent nausea and vomiting in motion sickness iridocyclitis

Question 38

adverse effect of scopolamine

Answer 38

blocks short term memory | sedation