Cholinergic agents

Question 1

Bethanechol

Answer 1

Direct agonist
Clinical: postop ileus, neurogenic ileus and urinary retention

Action: activates bowel and baldder smooth muscle, resistant to AchE

Question 2

Carbachol

Answer 2

Direct agonist
Clinical: gluacoam, pupillary contraction, and relef of intraocular pressure

Action: carbon copy of acetylcholine

Question 3

Pilocarpine

Answer 3

Direct agonist
Clinical: potent stimulator of sweat, tears, and saliva
Open angle and closed angle glaucoma

Action: contracts ciliary muscles of eye (open-angle glaucoma), pupillary sphincter (close-angle glaucoma)
Resistant to AchE

“You cry, drool, and sweat on your pillow”

Question 4

Metacholine

Answer 4

Direct agonist
Clinical: to dx asthma
Stimulates Muscarinic receptor in the airway

Question 5

Neostigmine

Answer 5

Indirect, anticholinesterases
Clinical: postop and neurogenic ileus and urinary retention, myasthenia gravis, reversal of neuromuscular junction blockade

Action: increases endogenous ACH
NEO CNS= NO CNS penetration

Question 6

Pyridostigmine

Answer 6

Indirect, anticholinesterases
Clinical: myasthenia gravis (long acting)
Does NOT penetrate CND

Increase endogenous ACH and increase strength

pyRIDostiGMine gets RID of Myasthenia Gravis

Question 7

Edophonium

Answer 7

Indirect, anticholinesterases

Clinical: diagnosis of MG (extremely short acting)

Question 8

Physostigmine

Answer 8

Indirect, anticholinesterases
Clinical: anticholinergic toxicity (crosses BBB => CNS)

PHYsostigmine PHYxes atropine overdose

Question 9

Dopnepezil

Answer 9

Indirect, anticholinesterases

Alzhemier’s disease

Question 10

What to look for in cholinomimetic agents?

Answer 10

Watch for exacerbation of COPD, asthma, and peptic ulcer when giving to susceptible patients

Question 11

Cholinesterase inhibitor poisoning

Answer 11

Often due to organophosphate, su chas parathion that irreversibly inhibit ACHE

Diarrhea, urination, miosis, bronchospasm, bradycardia, excitation of skeletal muscle and CNS, lacrimation, sweating, and salivation

Antidote: atropine + pralidoxime (regenerates active AchE)

Organophosphate: components of insecticides, often seen in farmers.

Question 12

Atropine, homatropine, tropicamide

Answer 12

Muscarinic antagonist

EYE
Application: produces mydriasis and cycloplegia

Question 13

Benztropine

Answer 13

Muscarinic antagonist

CNS
Applcation: Parkinson’s
“Park my BENZ”

Question 14

Scopolamine

Answer 14

Muscarinic antagonist

CNS
Motion sickness

Question 15

Ipratropium, tiotropium

Answer 15

Muscarinic antagonist

Respiratory
COPD, asthma
“I PRAy I can breathe soon”

Question 16

Oxybutynin

Answer 16

Muscarinic antagonist

GU
Reduces urgency in mild cystitis and reduce bladder spasm

Question 17

Glycopyrrolate

Answer 17

Muscarinic antagonist

GU and respiratory
Parenteral: pre op use to reduce airway secretion
Oral: drooling and peptic ulcer

Question 18

Atropine

Answer 18

Muscarinic antagonist
Used to treat bradycardia and ophthalmic application

Eye: increase pupil dilation, cycloplegia
Airway: decrease secretion
Stomach: decrease secretion of acid
Gut: decrease motility
Bladder: decrease urgency in cystitis

Toxicity: increase temp (due to decreased sweating), rapid pulse, dry mouth, dry/flushed skin, cycloplegia, constipation, disorientation

Skeletal muscle and CNS excitation mediated by nicotininc receptors.

Can cause acute angle-closure glaucoma in elderly (due to mydriasis), urinary retention in men with BPH, and hyperthermia in infants

Jimson weed => gardener’s pupil (mydriasis due to plant alkaloids)