Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
What are cholinomimetic drugs?
|
They mimic parasympathetic activity "rest/digest".
Muscarinic agonists |
|
Direct acting muscarinic agonist agents
|
Carbachol
Bethanechol Acetylcholine Methacholine Pilocarpine Cevimeline Muscarine |
|
Direct acting muscarinic agonist agents MOA
|
Bind to and activate muscarinic receptors
|
|
REMEMBER
|
Heart --> decrease HR
Blood vessels --> vasodilation (via NO) Ciliary muscle --> contraction/near vision Irish sphincter --> miosis GI tract --> increase activity Bladder --> micturation |
|
What would be the problem with using ACh as a drug?
|
Too nonspecific and very rapidly hydrolyzed by AChE and pseudo AChE
|
|
What are the therapeutic uses of Bethanechol?
|
Postoperative abdominal distension and urinary retention
|
|
What are the therapeutic uses of Pilocarpine?
|
Miotic
OAG NAG Sjogren's syndrome Radiation induced dry mouth |
|
What effect does muscarnic receptor activation have in teh eye?
|
Contract ciliary muscle
Contract iris sphincter--miosis |
|
How is Pilocarpine used?
|
For radiation of cancer in head or neck or for Sjogren's syndrome --> decreased salivary secretion --> Pilocarpine --> activate M receptor --> increased salivation
|
|
What is Cevimeline used for?
|
Newer drug for Sjogren's syndrome (longer lasting)
|
|
What is Carbachol used for?
|
It is the 2nd line drug after Pilocarpine in the treatment of glaucoma.
|
|
What is Muscarine?
|
It is NOT a drug and is present in Inocybe and Clitocybe mushrooms; mushroom poisoning (mycetism)
|
|
What symptoms might you expect to see in a person who has mushroom poisoning from Inocybe mushrooms?
|
Adverse effects of muscarinic agonists
|
|
Direct acting muscarinic agonist
Adverse Effects? |
Salivation
Sweating Intestinal cramps/NVD Increased gastric acid secretion Hypotension Reflex tachycardia Difficulty breathing/asthma attack |
|
How does muscarine and barorecptors work together?
|
Muscarine --> M3 --> decreased BP --> baroreceptor --> CNS --> increased HR and force of contraction
|
|
What are the adverse effects of direct acting muscarinic agonists on the eye?
|
Contract cilicary muscle --> lens rounds out --> near vision (spasm of accomodation--blurry)
Contract iris sphincter --> miosis |
|
Indirect acting cholinomimetics
Reversible AChE inhibitor agents? |
"Stigmine" and "riums"
Physostigmine Neostigmine Pyridostigmine Edrophonium Edrophonium + Atropine Ambenonium Demecarium |
|
Indirect acting cholinomimetics
Reversible AChE inhibitor agents that work in CNS? |
Donepezil
Tacrine Rivastigmine Galantamine |
|
Reversible AChE inhibitors MOA
|
Slows down the hydrolysis of ACh by AChE.
|
|
What happens to acetylcholine in the presence of neostigmine?
|
Neo binds to enzyme and ACh can't hydrolyze --> prolonged activity of ACh at receptor
|
|
Where is the site of action of physostigmine?
|
All cholinergic synapses--not very specific.
|
|
What are the therapeutic uses of physostigmine?
|
Miotic
Treatment of glaucoma Reverses antimuscarinic effects from plants that contain muscarinic blockers and drugs that have antimuscarinic effects. Advantage: Lipid soluble |
|
What are the therapeutic uses of neostigmine and pyridostigmine?
|
Postoperative urinary retention and abdominal distention (Neo)
Myasthenia Gravis (both) |
|
What other agent can be used to treat postoperative abdominal distention and urinary retention?
|
Bethanechol
|
|
How can we increase muscle strenth in patients with MG?
|
Increase the concentration of ACh in the NMJ --> increased muscle strength
|
|
What is the duration of action of Neostigmine?
|
2 to 4 hours
|
|
What is the duration of action of Pyridostigmine?
|
3 to 6 hours
|
|
What is Edrophonium?
|
Analog of neostigmine
Less potent Shorter acting (3-4 minutes) IV only |
|
What are the therapeutic uses of edrophonium?
|
Diagnostic test for MG
Pt is weak --> give edrophonium --> improved muscle strength for 3-5 min. |
|
What are the other therapeutic uses of edrophonium?
|
Assesses the adequacy of treatment with neo
Differentiates between a myasthenic crisis and a cholinergic crisis |
|
How can one tell if the Neostigmine dose is too high?
|
Pt on neo --> weak --> give edrophonium --> decrease or no change in muscle strength --> Neo dose is too high
|
|
How can one tell if the Neo dose is too low?
|
Pt on neo --> weak --> give edrophonium --> increase in muscle strength --> neo dose is too low
|
|
How can too much neo produce muscle weakness?
|
There is no time for muscle cells to repolarize (Depolarization blockade)
|
|
What centrally acting reversible AChE inhibitors treat Alzheimer's Disease (AD)?
|
Donepezil
Tacrine Rivastigmine Galantamine |
|
What is the difference in the drugs that treat AD?
|
All drugs produce a similar improvement in cognitive function. The biggest difference is in the dosing and side effects.
|
|
Tacrine for AD
|
Many side effects (especially GI and hepatotoxic)
|
|
Donepezil for AD
|
Least GI side effects, 1 X d dosing
|
|
Galantamine for AD
|
Middle GI side effects, 1 x d dosing
|
|
Rivastigmine
|
Most GI side effects, 2 X d dosing
|
|
What is the newest drug for AD?
|
Memantine which is an NMDA antagonist
|
|
What is carbamate cholinesterase inhibitors used for?
|
Garden insecticides--low dermal absorption
|