Ch. 20 & Ch. 21- Cholinergic/Cholinergic Blocking Flashcards
What are cholinergic drugs?
Drugs that stimulate the parasympathetic nervous system
What are some other terms for cholinergic drugs?
Cholinergic agonists
Parasympathomimetics
What neurotransmitter do cholinergic drugs mimic the effect of?
Acetylcholine
What are the cholinergic effects of acetylcholine?
SLUDGE Salivation Lacrimation (tearing of eyes) Urination Diarrhea GI increased motility Emesis (vomiting)
What are nicotinic receptors and where are they located?
In both the sympathetic and parasympathetic nervous system. Cause constriction of blood vessels, increased BP, pupil constriction, increased motility
Why are nicotinic receptors named this?
Because they are stimulated by nicotine, in tobacco plant
What are muscarinic receptor and where are they located?
In smooth muscle, cardiac muscle, and glands. Post synaptically in the effector organs of the parasympathetic nervous system.
Why are muscarinic receptors named this?
They are stimulated by muscarine, found in mushrooms
How do cholinergic drugs work?
Either directly (go and block the receptor site) or indirectly (inhibit the enzyme or stimulate the post synaptic release of ACH at the receptor site)
How do indirect-acting (cholinesterase inhibitors) work?
They bind to cholinesterase in two ways
What are the two ways that indirect-acting (cholinesterase inhibitors) bind to cholinesterase?
Reversible- they bind to the cholinesterase for minutes to hours
Irreversible- they bind to cholinesterase and form and irreversible covalent bond. Must make new cholinterase in body
At recommended doses, which receptors do cholinergic drugs primarily effect?
Muscarinic receptors. These are many of the desired effects
At high doses, which receptors do cholinergic drugs primarily effect?
Nicotinic receptors. These are many of the undesired effects
What do direct acting drugs do?
Reduce intraocular pressure
How are direct acting drugs administered and why?
Topical application because of poor oral absorption
What is bethanechol?
A prototype direct acting drug that increases tone and motility of bladder and GI tract. R lazes sphincters in bladder and GI tract
What are indirect drugs? (Indirect acting cholinergic agonists)
Cause skeletal muscle contractions. Used to reverse neuromuscular blocking drugs, and reverse anticholinergic poisoning (antidote)
What are indirect acting drugs (indirect acting cholinergic agonists) commonly used for?
To treat mild to moderate Alzheimer’s disease (Donepezil)
What are adverse effects of cholinergic drugs a result of?
Overstimulation of the PSNS
What is ginkgo commonly used to treat?
organic brain syndrome, vertigo, tinnitus
What are the adverse effects of gingko?
GI upset, headache, bleeding, allergic skin reactions
What do cholinergic drugs stimulate and mimic?
Cholinergic drugs stimulate the PSNS and mimic the action of ACh
What is the antidote for cholinergics?
Atropine
What are the therapeutic responses we want from cholinergic drugs?
Increased bowel sounds, passage of flatus, BMs, urination within 60 min
