Cholinergic Drugs Flashcards
1
Q
bethanechol
A
Muscarinic Receptor Agonist
- choline ester
- Acetyl group of acetylcholine is replaced with a carbamyl. The N+ is permanently charged, reuslting in poor CNS absorption.
- Slowly hydrolized by AchE. Used topically for glaucoma.
2
Q
carbachol
A
Muscarinic Receptor Agonist
- choline ester
- A carbamyl added to acetyl choline. The N+ is permanently charged, reuslting in poor CNS absorption. Reduce binding to nicotinic receptors; selective for muscarinic receptors
- Slowly hydrolized by AchE. Used to promote GI and urinary tract motility when non-obstructive cause. (Binds receptor that relaxes sphincters and constricts smooth muscles.
3
Q
Methacholine
A
Muscarinic Receptor Agonist
- choline ester
- a beta-methyl group is added to acetocholine, reducing binding to nicotinic receptors. Selective for muscarinic receptors. Permanently charged = poor absorption into CNS.
- diagnosis of asthma.
4
Q
pilocarpine
A
Muscarinic Receptor Agonist
- tertiary amine
- tertiary amine N is not charged so this can penetrate CNS. It is not an ester so It is not hydrolized by cholinesterase. Longer duration of action than Ach.
- Sialogogue (Cause salivation) and a mitotic agent (constricts pupil)
5
Q
glycopyrrolate
A
Antimuscarinic
- quaternary amine
- poor CNS penetration
- Decrease oral secretions, GI Spasms, Treatment of saiallorrhea like in children with cerebral palsy. Treat peptic ulcer disease. Prevent bradycardia during surgical procedures.
6
Q
Oxybutynin
A
Antimuscarinic
- tertiary amine, M3 selective
- relief of bladder spasm after urologic surgery
7
Q
tolterodine
A
Antimuscarinic
- tertiary amine, M3 selective
- For urinary incontinence in Adults (M3 contracts smooth muscle and relaxes sphincters.)
8
Q
darifenacin
A
Antimuscarinic
- tertiary amine, M3 selective
- For urinary incontinence in Adults (M3 contracts smooth muscle and relaxes sphincters.)
9
Q
pirenzepine
A
Antimuscarinic
- tertiary amines, M1 selective
- inhibits gastric acid secretion. Little effect on smooth muscle or CNS
- used in peptic ulcer disease, but not so much anymore
10
Q
tropicamide
A
Antimuscarinic
- tertiary amine
- mydriatic (pupil dilation), cycloplegic. Much shorter duration of action than atropine. (.25 days rather than a week)
11
Q
cyclopentolate
A
Antimuscarinic
- tertiary amine
- mydriatic (pupil dilation), cycloplegic. Much shorter duration of action than atropine. (1 day rather than 1 wk)
12
Q
Trimethophan
A
Nicotinic Receptor Antagonists
- Ganglion Blocking drug
- Treatment of hypertensive emergencies, rarely used bc of bad side effects. Used to produce controlled hypotension during surgery to decrease bleeding.
13
Q
pancuronium
A
Nicotinic antagonist
- like steroid hormones, part of it mimics ach but bulkiness keeps the channel from opening.
- depolarizing blockade can be reversed by increasing concentration of normal transmitter, i.e. Ache
- Block access of Ach to receptor thereby preventing depolarization of membrane block channel in CLOSED position
14
Q
tubocurarine
A
Nicotinic antagonist
- arrow poison
- depolarizing blockade can be reversed by increasing concentration of normal transmitter, i.e. Ache
- Block access of Ach to receptor thereby preventing depolarization of membrane block channel in CLOSED position
15
Q
Succinylcholine
A
Neuromuscular Blocking Drug
- two acetylcholines connected together. ONLY depolarizing drug in use in US. Duration of action is five to ten minutes. Used in surgery.
- Phase I block: channel opens. Depolarized membranes remain depolarized and unresponsive to subsequent impulses. Flaccid paralysis results.
- Phase II block: desensitizing: continued exposure to the drug, depolarization decreases, membrane becomes repolarized some how, channels behave as though in a prolongued closed state even though they are in a prolongued open state.
16
Q
Edrophonium
A
Indirect-acting Cholinomimetics -Acetylcholinesterase Inhibitors
- simple alcohol that non-covalently inhibits ACHE, short diration of action (Competes with Ach for binding)
- Use as a diagnostic test when patients exhibit muscle weakness. (It will mitigate weakness if blockade due to competitive Ach receptor antagonists or disease that affect NMJ)
- too asses adequacy of treatment for myaesthenia gravis.
17
Q
neostigmine
A
Indirect-acting Cholinomimetics -Acetylcholinesterase Inhibitors
- carbomate: can modify AChE and stays on AChE longer than acetyl group would stay on in case of acetylcholine… basically binds up the enzyme and holds onto it for a while.
- charged, poorly absorbed, no distribution in CNS.
- MG, ileus, reversal of neuromuscular blockade
18
Q
physostigmine
A
Indirect-acting Cholinomimetics -Acetylcholinesterase Inhibitors
- CAN GET INTO CNS - must be used carefully, used in overdose of antidepressants (?)
- well-absorbed from all sites
- glaucoma, reversal of neuromuscular blockade, used as a topical on the eye
