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72 Cards in this Set
- Front
- Back
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what is the prototype for muscarinic antagoonists |
Atropine
response changes as dose increases, CNS only seen in super high doses |
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whats scopolamine
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anti muscarinic
used transdermal for motion sickness can enter CNS |
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whats tropicamide
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anti muscarinic
short acting, used to dilate the eye *dont use in narrow angle glaucoma |
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what are the muscarinic antagonists (10)
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1. Atropine- no CNS, decrease bradycardia due to excess vagal tone, reverse AV block
2. Scopolamine- transdermal for motion sickness 3. Tolterodine- tx overactive bladder 4. Oxybutynin- prevent bladder spasm after prostate surgery 5. Glycopyrrolate- used in surgery to block vagal stim that will decrease HR. also used to decrease muscarinic side effects when neostigmine is used to tx MG 6. Dicyclomine- GI antispasmodic 7 Solifenacin- Mb selective, tx overactive bladder, little effect on salivaiton 8 Ipratropium/wont cross BBB, tx COPD, asthma 9. tiotropium- tx COPD, asthma 9. Tropicamide- dilate eye & cycloplegia, wont cross BBB 10. Diphenocylate atropine- given with opoids to decrease diarrhea |
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are the muscarinic antagonists specific for M1, M2, M3 etc
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not really
M3 selectives are: -tolterodine -solifenacin -darifenacin |
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in general what is the method of action for muscarinic antagonists
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antagonize the PNS
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which muscarinic antagonists wont enter CNS well
what does enter well |
No BBB:
-Atropine. so CNS effects until we ahve high doses -Ipratropium: asthma, COPD -Tiotropium: asthma, COPD Crosses BBB: scopolamine. sedation, amnesia, can cause euphoria and it abused. used transdermal for motion sickness |
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what are some naturally occuring muscarinic antagonists
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1. Belladona
2. jimson weed **these plants have atropine, the prototypical antimuscarinic that wont really cross the CNS |
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what are some antimuscarinisc that have a short duration, what are they used for
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Tropicamide, homatropine
**used to dilate the eye |
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how are antimuscarinics and diarrhea related
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antimuscarinic + opoid are used to tx diarrhea
**atropine + diphenoxylate |
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whats tolterodine
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muscarinic antagonist
tx overactive bladder M3 |
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what is oxybutinin
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muscarinic antagonist
prevent bladder spasm after prostate surgery |
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whats the mech of muscarinic antagonists
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competitive antagonists for M receptors, usually non specific (M3 selective are tolterodine, solifenacin, darifenacin)
dont affect Nicotinic R effect depends on PNS tone in the tissue, there is a dose related response *bigger effect in tissues where tone is high |
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what tissues are affected at the lowest dose of atropine? whats the progression of tissues affected as the dose of atropine is increased
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M antagonist- dose reponse, places with highest tone are affected first
1. Dry Mouth (M3) decreased sweating (M1) decreased lung secretion (M3) 2. Heart (M2) Eye (M3), tachycardia, blurred vision 3. GI (M3) GU (M3) decreased GI and urinary retention 4. CNS, ataxia, hallucinations, deliuium, coma |
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in what order are these tissues affected by atropine
heart eyes CNS mouth, sweat, lung GI GU |
1. Mouth, sweat, lung (you dry up)
2. Heart Eyes (tachycardia, blurry vision, cant accomadate) 3. GI GU (decreased activity, urine retention) 4. CNS (deliuirm, ataxia, coma) |
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if a patient is having tachycardia and blurred vision how much atropine were they given. what happens if thy are given less, what about more. what happens when toxic
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Heart/Eyes- moderate dose
Less: mouth, sweat, lungs dry up More: GI/GU upset, urine retention Toxic: CNS effects, Atropine will not normally enter CNS |
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what are some other drugs that will cause M blockade that we need to be in the look out for in the future
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1. antihistamine
2. antidepressants 3. antipsychotics |
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what are the CNS effects of Atropine and Scopolamine
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Atropine: wont readily cross BBB, CNS stim followed by depression (confusion, coma)
Scopolamine: crosses BBB, drowsiness/amnesia at lot and then at higher doses stim CNS (excitement, agitation, hallucinatation, coma) Euphoria, some abuse potential. Preanesthtic- sedation/amnesia |
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what is scopolamine used for other than as a transdermal motion sickness tx
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pre-anesthetic. will cross BBB and cause amnesia and sedation as well as dry bronchiole secretions
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how can balance btwn Ach and Dopamine be attained (when D receptors are blocked or dopamine reduced, as seen in antipsychotics and parkinsons)
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antimuscarinics can restore the balance
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how do antimuscarinics affect the eye
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well M3 causes meiosis and accomadation, this decreases intraocular pressure by opening up that angle
sooo... when they are blocked the eye dilates (mydriasis), the ciliary mm are blocked and the eye wont accomadate (cycloplegia) and no light relex, photophobia. Intraocular pressue can increase- dont use in narrow angle glaucoma, also dry eyes is a side effect ex tropicamide side |
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what is cycloplegia, what class of drug will cause it
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its when you cant accomadate, the ciliary mm is blocked
seen in M antagonists like tropicamide (also see photophobia bc loss of pulilary reflex and mydriasis. dont use in narrow angle glaucoma) |
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what is a contraindication for antimuscarinics in the eye
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well they dilate the eye and the iris shoves into the trabecular meshwork closing the angle and increasing intraocular pressure
DONT use M antagonists in ppl with narrow angle glaucoma |
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whats a common side effect of M antagonists in regards to the eye
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dry eye, blurred vision
seen with the 2 stage of atropine (ie first sweat/mouth/lungs then heart and eyes are affected) |
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what are the effects of a muscarinic antagonist on the heart (3) low dose, moderate, other
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M2 act in heart to decrease HR and decrease AV conduction in the ATRIA
so.. an antagonist can be used to overcome AV block 1. low dose, presynaptic M2 R stim to increase release of Ach 2. moderate dose, Post synaptic M2 are turned off, tachycardia 3. Presynaptic M2 remove tonic inhibition and increased release of NE |
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where are there Muscarinic R in the heart. what subtype, what does effect does a muscarinic antagonist have
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M2 receptors, pre and post synaptic
1. At low doses of Atropine the presynaptics are stim and increase release of Ach, we get bradycardia 2. Mod dose of Atropine stim post synaptic M2 in Sa node and we get tachycardia 3. Presynaptic M2 block will INCREASE NE release |
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what is the effect of muscarinic antagonist (atropine, scopolamine, tolterodine, oxybutynin, glycopyrrolate, dicyclomine, solifenacin, tropicamide, diphenoxylate) in the heart, who see this effect most and least
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it causes tachycardia bc vagal stim to decrease HR is not getting there (also presynaptic M2 block causes increase in NE)
remember the higher the tone the more effect we will see, the heart has lots of PNS tone in young healthy adults and so a large tachycardia is seen. in older folks and babies there is less of an effect seen (their vagal tone is less so will have less effect) |
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will a muscarinic antagonist affect the ventricles
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nope, innervation is in the atria to decrease HR and conduction
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antimuscarinics lead to increased ____ and ____ in the heart and so increase the risk of _____
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HR
AV conduction arrhythemia |
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what can reverse the effects of vagal discharge
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an antimuscarinic like atropine. we block vagal output so HR/CO wont drop too much if we are going to be stim the V nerve
ex glycopyrrolate *if you have laryngeal stim with intubation in surgery, pain, or something else that stim the vagus it can also affect the heart and decrease HR/CO |
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glycopyrrolate
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antimuscarinic
*used in surgery to prevent vagal response. we give this to prevent a decrease in HR. in surgery we can mess with the vagus nerve (ie laryngeal stim in intubation) which increases its rate which will decrease HR, we dont want this so we block it |
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atropine can be used to reverse (tachycardia/bradycardia) produced by _______
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bradycardia
*M agonists, cholinesterase inhibitors *An M agonist will cause brady cardia, it can be revered by an M antagonist |
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is atropine used in early MI, why or why not
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Yes
M antagonist so will cause increased HR and AV conduction. Blocking vagal input will increase AV conduction (overcome AV block and ensure HR wont slow too much) |
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whats the effect of antimuscarinic on BV
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no PNS innervation of BV so little effect on peripheral resistance
**recall M agonist will increase NO to cause vasodilation. an M antagonist will block this so there will be no drop in BP *when toxic atropine will cause vasodilation in the face to remove excess heat |
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wht happens to peripheral resistance when an antimuscarinic is given? what it was given after an M agonist
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not much, no PNS tone here
The M agonist will release NO and cause vasodilation. Atropine (or antoehr M antagonist) will totally block this so BP is not decreased |
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what happens to the face with atropine (antimuscarinic) toxicityq
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red, vasodilation to remove extra heat
**in teh body there is no PNS innervation on BV so little effect on TPR with atropine. BUT atropine will block the effect of M agonist (M agonist will cause vasodilation via NO and decrease BP. no drop in BP if atropine is given) |
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what M Receptor is in the lungs, what is the effect of stimulation, whats the effect of BLOCKING stim with a Muscarinic antagonist like atropine
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1. M3
2. Bronchoconstriction 3. they dilate bronchoiles for releif of acute asthma attacks (not a long term tx) tx COPD Ipratropium |
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what would be the best approach for asthma
adrenergic agonist adrenergic antagonist cholinergic agonist cholinergic antagonist |
Adrenergic AGONIST- B2
Muscarinic Antagonist- M3 (ipratropium) |
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who might benefic from smoking? (limson weed and belladona that is)
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Atropine, M antagonist
will block the constriction of M3 and cause dilation Smoking is good for...ASTHMATICS, go figure ;) atropine and others are good for acute asthma attacks but not chronic control. used to tx COPD Ipratropium |
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whats Ipratropium
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anti muscarinic
tx acute asthma Block M3 in lungs so block bronchoconstriction and allow for dilation |
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what type of drug can be used to inhibit salivary/respiratory secretions and inhibit laryngeal spasm before anesthesia
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Antimuscarinics
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ipratropium
what class tx for side effects |
Muscarinic antagonist
asthma, COPD dry mouth |
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what effects do anti muscarinics have in the GI tract
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M3 will stim peristalsis and relax sphincters
so if this is blocked we will have decreased digestion and contracted sphincters. drugs like dicyclomine used as antispasmotic, not really used to decrease acid |
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whats the emtimuscarinic that acts on the GI, what is its effect
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dicyclomine
*decrease motility and secretions *antispasmodic |
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how can we tx disrrhea
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antimuscarinic, atropine
opiod, diphenoxylate, lomotil *they potentiate one another to decrease GI motility. give together to decrease abuse of opiod |
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what does antimuscarinic do for bladder, what drugs are used for this
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well..M3 contract the bladder and relax the sphincter to help you pee, if you block this you block peeing. can use them in overactive bladder
tolterodine- M3 selective, wont enter CNS solifenacin- M3 selection, little effect on salivation oxybutynin/trospium- prevent overactive bladder after prostate surgery |
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what are the 3 drugs that are used to tx overactive bladder by blocking M3 R
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anti muscarinics
tolterodine- M3 selective, wont enter CNS solifenacin- M3 selection, little effect on salivation oxybutynin/trospium- prevent overactive bladder after prostate surgery |
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tolterodine- M3 selective, wont enter CNS
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M3 selective antagonist
tx for overactive bladder wont enter CNS Other antiM for overactive bladder: solifenacin- M3 selection, little effect on salivation oxybutynin/trospium- prevent overactive bladder after prostate surgery |
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solifenacin-
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antimuscarinic, M3 selective
tx overactive bladder little effect on salivation other M antagonists to tx overactive bladder tolterodine- M3 selective, wont enter CNS oxybutynin/trospium- prevent overactive bladder after prostate surgery |
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oxybutynin/trospium-
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antimuscarinic
prevent overactive bladder after prostate surgery other antiM that prevent overative bladder tolterodine- M3 selective, wont enter CNS solifenacin- M3 selection, little effect on salivation |
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what class
how is it used tropicamide |
anti muscarinic
used in eye to dilate and cause cycloplegia (lack of accomadation) for eye exams |
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what class
how is it used Diphenoxylate atropine |
antimuscarninc
tx diarrhea when used with opoid |
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what class
how is it used dicyclomine |
antimuscarinic
GI antispasmodic |
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what class
how is it used atropine |
anti muscarinic, the prototype
decrease bradycardia due to excess vagal tone ot reverse AV block |
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what class
how is it used Glycopyrrolate |
anti muscarinic
block excess vagal tone in sirgery decrease muscarninc side effects whatn neostigmine or other AchE inhibitors are used to tx MG |
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what class
how is it used ipratropium tiotropium |
antimuscarninc
tx asthma, COPD |
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what class
how is it used tolterodine |
prevent overactive bladder
antimuscarinic |
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what class
how is it used scopolamine |
anti muscarinic
tx motion sickness |
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what class
how is it used benxtropine |
decrease extrapyramidal sx caused by antipsychotics and parkinsons tx
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what antimuscarinic does...
1. No CNS, decrease bradycardia due to excess vagal tone, reverse AV block 2. - transdermal for motion sickness 3. - tx overactive bladder 4. - prevent bladder spasm after prostate surgery 5. - used in surgery to block vagal stim that will decrease HR. also used to decrease muscarinic side effects when neostigmine is used to tx MG 6. GI antispasmodic 7 - M3 selective, tx overactive bladder, little effect on salivaiton 8 wont cross BBB, tx COPD, asthma 9. tx COPD, asthma 9- dilate eye & cycloplegia, wont cross BBB 10. given with opoids to decrease diarrhea 11. used to tx excesspyramidal sx caused by antipsychotis or in parkinsons tx |
1. Atropine- no CNS, decrease bradycardia due to excess vagal tone, reverse AV block
2. Scopolamine- transdermal for motion sickness 3. Tolterodine- tx overactive bladder 4. Oxybutynin- prevent bladder spasm after prostate surgery 5. Glycopyrrolate- used in surgery to block vagal stim that will decrease HR. also used to decrease muscarinic side effects when neostigmine is used to tx MG 6. Dicyclomine- GI antispasmodic 7 Solifenacin- Mb selective, tx overactive bladder, little effect on salivaiton 8 Ipratropium/wont cross BBB, tx COPD, asthma 9. tiotropium- tx COPD, asthma 9. Tropicamide- dilate eye & cycloplegia, wont cross BBB 10. Diphenocylate atropine- given with opoids to decrease diarrhea 11. benztropine |
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what are some side effects of antimuscarinics
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1. Dry mouth
2. decreased bronchial secretions (decreased clearance of irritants) 3. tachycardia 4. mydriasis/cycloplegia 5. decreased GI motility 6. urinary retention 7. no sweat 8. hot dry skin, |
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what are some contraindications for antimuscarinic therapy
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1. narrow angle glaucoma (dont want that eye dilating)
2. old guys with BPH, antimuscarinics decrease peeing, they have a hard enoug htime peeing as it is |
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what do Benign Prostatic Hypertrophy and antimuscarinics have in common
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well M3 in the bladder increase peeing so if we block them it decreases peeing. men with BPH have a hard time peeing as is and so antimuscarinics are contraindicated in them
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what are hte side effects of atropine poisiong
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Dry as a bone
red as a beat mad as a hatter blind as a bat |
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whats side effects with toxicitiy make you...
red as a beet, mad as a hatter, blind as a bat and dry as a bone |
Atropine poision
*antimuscarinic |
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who is more sensitive to becoming dry as a bone, mad as a hatter, red as a beat nad blind as a bat (also increased HR)
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kids, more sensitive to hyperthermia
more sensitive to atropine poision, can be via jimson weed, trocipamide in eye exams or diphenoxylate atropine for diarrhea |
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poision with what anticholinergic results in psychosis
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scopolamine (the transdermal motion sickness)
**it crosses CNS **kids esp prone (even with patch, dont take it in hot tub) |
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what are 3 classes of drugs that can have poision as seen in anti muscarinics (red, dry, blind, mad, tachycardia)
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tricyclic antidepressants
antihistamines antipsychotics **conversly, atropine (antimuscarinic) can be used to tx poisioning of AchE inhibitors, and Muscarinic poisioning |
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how can you tx anti muscarinic poisioning
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AchE inhibitor
diaxepam ice to control body temp assist respiration |
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how is AchE poisioning treated
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atropine
*if you have too much Ach in cleft you can block the M receptors with atropine to tx. *nerve gas and organophosphates are AchE inhibitors that are commonly seen in toxic doses. these increase the Ach. Atropine will then BLOCK the M receptors to block muscarinic effects, we know to stop atropine when eyes dilate and mouth drys |
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if we have AchE poision we tx with ____ untill _____
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atrpoine
mouth drys, eyes dilate (indicated m receptors are being blocked!) |
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how is mucarine poisioning treated?
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atropine
Muscarine is a M agonist, and atropine is an M antagonist! *Muscarine poision seen with mushrooms |
