Cholinergic Agonists

Question 0

Methacholine

Answer 0

Carefully, for dx of bronchial hyperreactivity and asthmatic conditions

No nicotinic action, Muscarinic only
Slightly susceptible to cholinesterases

Question 1

Acetylcholine

Answer 1

Rapidly hydrolyzed by cholinesterases

Limited clinical use:
Intraocularly to produce miosis
During diagnostic coronary angiography for vasodilation
Diagnose vasospastic angina, causes smooth mm contraction

Question 2

Carbachol

Answer 2

Wide angle glaucoma, when other cholinomimetics no longer effective

Nicotinic and muscarinic action
Negligible susceptibility to cholinesterase

Question 3

Bethanechol

Answer 3

Stimulate bladder and GI movement

Used postoperatively after abd surgery and postpartum

Alternative to pilocarpine for xerostomia

Muscarinic action only
Negligible susceptibility to cholinesterase

Question 4

Contraindications for use of choline esters

Answer 4

Asthma
Urinary obstruction
Acid-peptic disease

Question 5

Pilocarpine

Answer 5

Plant alkaloid
Primarily muscarinic activity

Miotic agent for wide-angle glaucoma
Narrow-angle glaucoma, used preop with physostigmine (anti-cholinesterase)

Orally for xerostomia

Question 6

Muscarine poisoning

Answer 6

Salivation and lacrimation
Nausea, vomiting
Headache, visual disturbance
Bronchospasm
Bradycardia, hypotension
Shock

Readily reversed with atropine