Chapter 14 - Muscarinic Agonists and Antagonists Flashcards
Cholinergic drugs are agents that influence the activity of
cholinergic receptors.
Cholinergic drugs are drugs that act directly on cholinergic receptors where they either mimic or block the actions of
acetylcholine
cholinesterase inhibitors influence cholinergic receptors indirectly by preventing the
acetylcholine
What are the six categories of cholinergic drugs
- Muscarinic agonists
- Muscarinic antagonists
3 Ganglionic stimulationg agents - Ganglionic blocking agents
- Neuromuscular blocking agents
6.Cholinesterase inhibitors
The muscarinic agonists, represented by bethanechol, selectively mimic the effects of acetylcholine at _____receptors
muscarinic receptors.
The muscarinic antagonists, represented by atropine, selectively block the effects of acetylcholine (and other muscarinic agonists) at _______ receptors
muscarinic.
Ganglionic stimulating agents, represented by nicotine itself, selectively mimic the effects of acetylcholine at _____ receptors
nicotinic N
Ganglionic blocking agents, represented by mecamylamine, selectively block _______
ganglionic nicotinic N receptors
Neuromuscular blocking agents, represented by d-tubocurarine and succinylcholine, selectively block the effects of acetylcholine at ______ receptros at the ________
nicotinic M receptors ; neuromuscular junction.
cholinesterase inhibitors, represented by neostigmine and physostigmine, prevent the breakdown of acetylcholine
acetylcholinesterase, and thereby increase the activation of all cholinergic receptors.
Anticholinergics may _____ lactation in some women, resulting in _____ production of breast milk.
inhibit; decrease
list the three major subtypes of cholinergic receptors
- muscarinic
- Nicotinic N
- NIcotinic M
Bethanechol : [Urecholine, Duvoid image]
Receptor :
Usage :
- (muscarinic agonist) activates muscarinic receptors of urinary tract - This relaxes the trigone and sphincter muscles and increases voiding pressure.
- urinary retention (mostly postpartum or postoperative)
Cevimeline [Evoxac]?
Recepor:
Usage:
- (muscarinic agonist) activationg muscarinic receptors on residual healthy tissue in salivary glands, thereby promoting salivation
- Used for dry mouth in patients with Sjogren’s syndrome
Pilocarpine?
Receptor:
Usage:
- muscarinic agonist
- topical therapy of glaucoma, an ophthalmic disorder characterized by elevated intraocular pressure with subsequent injury to the optic nerve.
Acetylcholine?
Receptor:
Usage:
- (muscarinic agonist) Activates muscarinic cholinergic receptors and all nicotinic cholinergic recepors
- Used to produce rapid miosis following lens delivery in cataract surgery.
Muscarine is of historic interest because
of its role in the discovery of cholinergic receptor subtypes. The drug has toxicologic significance because of its presence in certain poisonous mushrooms.
Muscarinic poisoning can result from ingestion of certain _____ and from overdose of ______ and ______
mushrooms ; direct acting muscarinic agonists and cholinesterase inhibitors.
Manifestations of muscarinic poisoning result from excessive activation of ______?
muscarinic receptors
What is the treatment of muscarinic poisoning?
atropine (muscarinic blocking agent)
Muscarinic antagonists competitively block the actions of ________
acetylcholine at muscarinic receptors.
the muscarinic antagonists are also known as _______ drugs
parasympatholytic
What are the four major symptoms of overactive bladder?
- urinary urgency
- urinary frequency
- nocturia
- urge incontinence
What are the 3 three designated muscarinic receptor subtypes?
M1, M2, M3,
