Term
| Where do we see what types of muscarinic receptors? What does muscarinic do overall? |
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Definition
-M1; Glands of GI
-M2; Heart (SA and AV nodes only)
-M3; The rest
-Overall the muscarinic system is PANS (except for sweat glands) and acts to increase secretions and smooth muscle contraction, and decrease heart function
-Note; there is no drug that selectively activates these |
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Term
| What actions are solely SANS and PANS? |
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Definition
-Blood vessels are solely SANS
-GI is almost all PANS
-Important because if we stimulate the ganglia (all same Nn receptors) we will see SANS blood vessel over-action (constriction predominates via a1), PANS GI over-action (diarrhea), and mixed everything else
-Note that blood vessels have M receptors that are not innervated (act via NO stimulation); so **direct acting M agonist will produce vasodilation when given systemically
-Indirect, such as AChE inhibitors will have no effect here |
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Term
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Definition
-Blocks choline uptake
-No clinical use
-Sounds like "half-choline"... maybe it halves it |
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Term
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Definition
-Interacts with *synaptobrevin to inhibit ACh release
Uses;
-Blepharospasm; eye twitches
-Strabismus; cross eye
-Dystonia; sustained muscle contraction
-Cosmetics
-Causes paralysis for a few months |
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Term
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Definition
-M agonist (direct cholinomimetic)
Uses;
-Ileus; low gut motility
-Urinary retention
-Would have have to deal with the miosis, increased accommodation, bradycardia, etc. as side effects |
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Term
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Definition
-M agonist (direct cholinomimetic) & a little N action
Uses;
-Dx of bronchial hyperreactivity (will cause wheezing) |
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Term
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Definition
-M agonist (direct cholinomimetic)
Uses;
-Glaucoma (topical)
-Xerostomia; dry mouth |
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Term
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Definition
-AChE inhibitor (indirect cholinomimetic)
Uses;
-**Dx of myasthenia (short acting, so can't treat); see increased muscle tone
-Will differentiate from cholinergic crisis (desensitization because of too much ACh) |
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Term
| Neostigmine, pyridostigmine? |
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Definition
-AChE inhibitor (indirect cholinomimetic)
-No CNS entry (quat. amine)
Uses;
-Rx of myasthenia gravis (longer acting than edrophonium)
-Reversal of nondepolarizing NM blockers (these are the "-curare" types of drugs given before surgery for flaccid par.) |
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Term
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Definition
-AChE inhibitor (indirect cholinomimetic)
-CNS entry (tert. amine)
Uses;
-Rx of glaucoma
-**Atropine overdose (because crosses BBB); it's a comp. M inhibitor |
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Term
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Definition
-AChE inhibitor (indirect cholinomimetic)
-Enters CNS (lipid soluble)
Uses;
-Rx of Alzheimer disease |
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Term
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Definition
-AChE inhibitor (indirect cholinomimetic)
-Lipid soluble (enter brain)
-Irreversible inhibition (lowers Vmax)
Uses;
-Rx of glaucoma (echothiophate)
-Toxicity in insecticides (**parathion & malathion) and sarin nerve gas |
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Term
| What are the effects of AChE inhibitor poisoning? How do we treat? |
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Definition
FOR ACUTE--------------
DUMBBELSS;
-Diarrhea
-Urination
-Miosis
-Bradycardia
-Bronchoconstriction
-Excitation (muscle and CNS, muscle eventually paralyzed)
-Lacrimation
-Salvation
-Sweating
Treatment;
-*Atropine (a competitive M antagonist)
-*Pralidoxime (2-PAM) (regenerates AChE); does not work after aging (Organic group leaves P on AChE via hydrolysis)
-Aging takes a few hours with parathion and malathion, but only a few minutes for sarin nerve gas
FOR CHRONIC-------------
-Causes demyelination (bc lipid soluble)
-Gives peripheral neuropathy (nothing to do with AChE)
-Similar effects to MS, and also with no treatment |
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Term
| Muscarinic antagonist effects/side effects? |
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Definition
Effects (mostly from SANS taking over);
-Decreased secretions (dry mouth)
-Mydriasis and cycloplegia (blurred from lack of acc.)
-Hyperthermia (no sweating--->vasodilation & redness)
-Sedation
-*Tachycardia (with broadening of QRS complex--> Torsades de Pointes arrhythmia)
-Urinary retention (symp. = store) and constipation
-Behavioral excitation & hallucinations (convulsions, coma)
Three C's for overdoses of any M antagonist;
-Cardiotoxicity
-Convulsions
-Coma |
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Term
| What are the other classes of drugs which have antimuscarinic side effects that we might not usually think of as antimuscarinic(6)? Treatment with overdose? |
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Definition
-Antihistamines
-Tricyclic antidepressants
-Antipsychotics
-Quinidine
-Amantadine
-Merperidine
-For all of these we need to worry about the side effects seen in atropine
-Treat with physostigmine for overdose |
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Term
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Definition
-Muscarinic antagonist (*the major one)
-Tert. amine (enters CNS)
Uses;
-Antispasmodic (of sm. muscle)
-Antisecretory
-Antidiarrheal
-AChE inhibitor OD
-Opthalmology (but really long action, like a few days) |
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Term
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Definition
-Muscarinic antagonist TROPIcamide
Uses;
-Ophthalmology (topical) |
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Term
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Definition
-Muscarinic antagonist (iprATROPIum)
-No CNS entry
Uses;
-Asthma and COPD (inhalant, decreases vol. of secretion, not viscosity) |
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Term
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Definition
-Muscarinic antagonist (nothing in name)
Uses;
-OTC in motion sickness preparation; causes sedation and short-term memory block
-Acts on the vestibular receptors which are M
-Antihistamines are also often used for motion sickness |
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Term
| Benztropine & trihexyphenidyl? |
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Definition
-Muscarinic antagonist (benzTROPINE, nothing for other)
Uses;
-**Parkinsonism; either from the disease or induced by antipsychotics |
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Term
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Definition
-N1 (ganglionic) blocker
-No clinical use; will wipe out entire ANS |
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Term
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Definition
-N1 (ganglionic) blocker
-No clinical use; will wipe out entire ANS |
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Term
| What can we expect in a ganglionic blockade? What are the two drugs? |
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Definition
Reduced predominant nerve tone;
-PANS is dominant where there's dual innervation & the gut
-SANS is dominant for vasculature (constriction via a1 is dominant tone over B2) & sweat
-Also, will see loss of changes in things controlled by the ANS, such as in pupil size with light (it will be a bit big because of predominate PANS btw)
-Direct acting drugs will still have an effect
-Reflex brady/tachycardia will be blocked, however
Drugs;
-Hexamethonium
-Mecamylamine |
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