Term
|
Definition
|
|
Term
| What competitively blocks mAchR's? |
|
Definition
|
|
Term
| What are muscarinic receptors couple with to produce downstream effects? |
|
Definition
|
|
Term
| Which mAchR's couple with Gq? |
|
Definition
|
|
Term
| Which mAchR's couple with Gi? |
|
Definition
|
|
Term
| Effect
mAchR activation of Gq? |
|
Definition
| increase cytosolic calcium => stimulatory |
|
|
Term
| Effect
mAchR activation of Gi? |
|
Definition
| increase potassium conductance & decrease AC => inhibitory |
|
|
Term
| Do muscarinic agents (agonist & antagonist) show selectivity for mAchR's? |
|
Definition
|
|
Term
| What is muscarinic activity of the CNS associated with? |
|
Definition
|
|
Term
| What account for the majority of CNS agonists? |
|
Definition
| quaternary amines that don't cross the BBB |
|
|
Term
| What is the prototype anti-muscarinic drug? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| delirium, hallucinations,coma, death |
|
|
Term
| What are the 3 ways aropine is administered? |
|
Definition
| PO, parenterally, topically |
|
|
Term
|
Definition
| natural alkaloid (from Atropa belladonna- same as atropine) |
|
|
Term
| Why is scopolamine given thru an adhesive patch for motion sickness? |
|
Definition
| topical absorption is very effective |
|
|
Term
| What metabolizes both atropine & scopolamine? |
|
Definition
|
|
Term
| How are atropine & scopolamine both excreted? |
|
Definition
|
|
Term
MOA
atropine & scopolamine |
|
Definition
| competitive antagonists of mAchR |
|
|
Term
| How is scopolamine different from atropine in effects? |
|
Definition
| produces 100x greater CNS depression => anxiolytic, hypnotic, anti-motion sickness, & amnestic effects |
|
|
Term
| What mediates atropine & scopolamine effects on CNS? |
|
Definition
| their muscarinic blocking action at cholinoceptive sites in brainstem & cortex |
|
|
Term
| How were the amnestic effects of scopolamine used as an advantage? |
|
Definition
| In preoperative medication or childbirth |
|
|
Term
| Is delirium & hallucinations also seen with scopolamine? |
|
Definition
| yes, but unlike atropine where it's only seen in toxic levels, they can be seen at therapeutic dose levels with scopolamine |
|
|
Term
| What is atropine used for clinically? |
|
Definition
| alleviate motor Sx of Parkinson's |
|
|
Term
| What synthetic muscarinic antagonist is used to alleviate Parkinson's Sx? |
|
Definition
| Benztropine (you Park your Benz) |
|
|
Term
|
Definition
|
|
Term
| What are the atropine SE? (think mnemonic) |
|
Definition
Red as a beet
Dry as a bone
Blind as a bat
Mad as a hatter
Hot as a hare |
|
|
Term
| What autonomic innervation does the eye recieve? |
|
Definition
|
|
Term
| What is controlled by the PS in the eye? |
|
Definition
1) sphincter pupillae of iris
2) ciliary muscle controling lens shape |
|
|
Term
What of the PS in the eye are mAchR agonist therapeutic targets?
mAchR antagonist therapeutic targets? |
|
Definition
agonist: sphincter pupillae of iris
antagonist: ciliary muscle of lens |
|
|
Term
| What synthetic mAchR agonist is used to cause miosis? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Can Carbamylcholine bind only to mAchR? |
|
Definition
| no, it can also bind nAchR |
|
|
Term
| Why is Carbamylcholine only employed as a topical mitoic agent? |
|
Definition
| too much of a widespread activity |
|
|
Term
| What is special about Carbamylcholine? |
|
Definition
Not broken down by cholinesterases
(note: is this done by something else, or does this lead to a long lasting effect?) |
|
|
Term
| What in the eye is controlled by SS? |
|
Definition
| radially oriented fibers of the iris |
|
|
Term
| When PS & SS of the iris are stimulated, what occurs? |
|
Definition
| both cause contraction => opposition to eachother |
|
|
Term
Effect
mAchR agonist in the eye |
|
Definition
|
|
Term
| How can mAchR agonists in glaucoma cause reduced intraocular pressure? |
|
Definition
| enhance drainage of intraocular fluid via canal of Schlemm |
|
|
Term
| What natural teritary amine is used for topical glaucoma miotic effect? |
|
Definition
|
|
Term
| Which AchR do pilocarpine work on? |
|
Definition
|
|
Term
| Why might pilocarpine be used to treat salivary disfunction or dry mouth? |
|
Definition
|
|
Term
Effect
mAchR antagonist in the eye |
|
Definition
|
|
Term
| Why isn't atropine used for mydriasis? |
|
Definition
|
|
Term
| What topical mAchR antagonist is shorter-acting and therefore more suitable for mydriasis effect? |
|
Definition
|
|
Term
|
Definition
|
|
Term
Effect
Contraction of lens ciliary muscle |
|
Definition
| increase lens convexity => focus of near objects |
|
|
Term
| What do cholinergic agonists do to vision focusing? |
|
Definition
|
|
Term
| What do cholinergic antagonists do to vision focusing? |
|
Definition
|
|
Term
| Why is atropine not given in glaucoma? |
|
Definition
| can lead to dangerous increase of pressure in the eye |
|
|
Term
|
Definition
| paralysis of ciliary muscle by mAchR antagonist => blurred near vision (focus in distance only) |
|
|
Term
| What is the typical SE of tropicamide? |
|
Definition
|
|
Term
| What mAchR receptors does the heart possess that decreased cellular activity when stimulated? |
|
Definition
|
|
Term
| Where is muscarinic action on the heart directed? |
|
Definition
|
|
Term
| What does M2 activation in the heart do? |
|
Definition
1) slows HR
2) decreased force of contraction
3) suppresses AV conduction |
|
|
Term
| What major effects does Ach have on atrial pacemaker cells? |
|
Definition
| 1) AP => shortened due to increased K+ permeability, or threshold may not even be met.
2) diastolic depolarization phases of cycle => steeper slope caused by hyperpolarization |
|
|
Term
| What causes the negative ionotropic action of Ach on atrial tissue? |
|
Definition
| shortened AP duration since it shortens the release & influx of Ca2+ => weaker contraction |
|
|
Term
| When are vascular Ach responses the most prominent pharmacological effect? |
|
Definition
|
|
Term
| What mAchR receptors are avilable in vasculature? |
|
Definition
|
|
Term
Effect
mAchR binding in vasculature |
|
Definition
|
|
Term
| When the M3 is bound in the blood vessel, what does the increase in incracellular calcium cause? |
|
Definition
| EDRF (endothelial-derived relaxing factor) to be realeased & diffuse to smooth muscle |
|
|
Term
|
Definition
|
|
Term
| How is EDRF (NO) derived? |
|
Definition
| calcium stimulated NO synthase |
|
|
Term
| What happens to BP & HR when mAchR is activated in vasculature? |
|
Definition
| decreased BP w/ reflex tachycardia |
|
|
Term
| When are Ach effects ONLY seen in the vasculature? |
|
Definition
| low doese IV administration (since Ach is metabolized so quickly in the plasma) |
|
|
Term
| Is reflex tachycardia seen in low dose Ach IV administration? |
|
Definition
| yes, due to dilation of the blood vessels |
|
|
Term
| What happens when high does of Ach is administered IV? |
|
Definition
| cardiac depression through Ach action on M2 receptors |
|
|
Term
| What happens if you give extra high IV dose of Ach? |
|
Definition
| Complex results due to cadiac stimulation via SS nAchR => NE release |
|
|
Term
| Why would cardiac stimulation be prominant if atropine is given prior to Ach administration? |
|
Definition
| mAchR are blocked, but nAchR are not. The only nAchR's not coupled with mAchR's are SS => cardiac stimulation |
|
|
Term
| Why does atropine, if administered alone, typically produce prominent tachycardia, but have no effect on BP? |
|
Definition
| BP is regulated by factors outside of AchR and atropine would have no effect on them. |
|
|
Term
| Why does atropine cause skin to become red, warm, & dry? |
|
Definition
Redness is due to vasodilation via reflex mechanism
Warm & dry is due to the blocking of sweat |
|
|
Term
| Why is atropine toxicity more likely to cause death in young children? |
|
Definition
| They are less capable to handle hyperthermic effects |
|
|
Term
| Why is atropine given after a MI? |
|
Definition
| to treat sinus bradycardia |
|
|
Term
| What effect does mAchR agonists have on GI smooth muscle from lower esophagus to rectum? |
|
Definition
| increased tone & motility |
|
|
Term
| What are the only muscles in the GI that relax due to mAchR agonists? |
|
Definition
| sphincter muscles (except lower esophageal sphicter which contracts) |
|
|
Term
| Which mAchR's mediate GI Ach effect? |
|
Definition
|
|
Term
|
Definition
| synthetic quaternary amine |
|
|
Term
|
Definition
| Tx of GI or urinary stasis, esp. post-partum or post-op. |
|
|
Term
| How is bethanechol similar to Carbamylcholine? |
|
Definition
| not metabolized by cholinesterases (or pseudocholinesterases) |
|
|
Term
| Why can't you give bethanechol when there's a mechanical GI or urinary obstruction? |
|
Definition
| will caused increased pressure of the lumen and may cause perforation |
|
|
Term
| What AchR do bethanechol work on? |
|
Definition
|
|
Term
| Why may atropine be used to treat mild diarrhea? |
|
Definition
|
|
Term
| Why was atropine previously used to treat peptic ulcer/gastric reflux? |
|
Definition
| contriction on esophogeal sphincter & decrease in HCl secretion of stomach |
|
|
Term
| Why shouldn't atropine be used to treat peptic ulcer? |
|
Definition
| decreased GI motility will keep acids in the stomach, even tho will slow some HCl secretion |
|
|
Term
|
Definition
|
|
Term
|
Definition
| spasmolytic of GI (decrease spasms) => hypermotility Tx |
|
|
Term
| Would atropine or propantheline be DOC for GI hypermotility? |
|
Definition
| propantheline b/c its a quaternary amine (they're better in GI, biliary, & urinary spasm Tx) |
|
|
Term
| What muscle of the bladder is stimulated by mAchR to faciliate urination? |
|
Definition
|
|
Term
Effect
mAchR antagonist on bladder |
|
Definition
|
|
Term
| What direct mAchR agonist is used to promote micturation (urination)? |
|
Definition
|
|
Term
| What indicrect mAchR agonist (i.e. AchE inhibitor) is also selective for promoting micturation (& GI motility)? |
|
Definition
|
|
Term
| What atropine SE are men with prostatic hyperplasia particularly sensitive to? |
|
Definition
|
|
Term
| What 2 mAchR antagonist variants are specifically for urge incontinence & post-op bladder spasms? |
|
Definition
|
|
Term
| What metabolizes oxybutynin? |
|
Definition
|
|
Term
| What metabolizes Tolterodine? |
|
Definition
|
|
Term
Structure
Oxybutynin & Toterodine |
|
Definition
|
|
Term
Effect
mAchR agonists on uterus |
|
Definition
| very sm. increase in tone/contractions |
|
|
Term
Effect
mAchR agonist in lung |
|
Definition
| bronchiolar smooth muscle contraction |
|
|
Term
| What mAchR receptors are in the lungs? |
|
Definition
|
|
Term
| What patients are especially sensitive to bronchiolar constriction of mAchR agonists? |
|
Definition
|
|
Term
|
Definition
| synthetic quaternary amine |
|
|
Term
| What mAchR's do methacholine show preference for? |
|
Definition
|
|
Term
| What is methacholine used for? |
|
Definition
Perviously: tachycardia
Currently: Aerosol form for Dx of bronchial airway hyper-reactivity in subclinical asthma |
|
|
Term
| Why does methacholine have a longer duration of action than Ach? |
|
Definition
| not metabolized by pseudocholinesterase & slowly degraded by AchE |
|
|
Term
| Why was atropine formerly smoked as afolk remedy? |
|
Definition
| mAchR antagonist => bronchial dilation |
|
|
Term
| What mAchR antagonist structure is preferred to cause bronchial dilation? |
|
Definition
|
|
Term
| What 2 quarternary amines are administered via aerosol to Tx emphysema & chronic bronchitis? |
|
Definition
1) ipratropium
2) tiotropium |
|
|
Term
| How is tiotropium different from ipratropium? |
|
Definition
| longer half-life & less antagonistic activity on M2 receptors |
|
|
Term
Effect
mAchR agonists on glands |
|
Definition
|
|
Term
| Why are mAchR agonists used to treat dry mouth? |
|
Definition
| increase salivary secretion |
|
|
Term
| What mAchR agonist (previously discussed) is used for salivary & sweat gland stimulation? |
|
Definition
|
|
Term
| What recently approved synthetic mAchR agonist is also used for Tx of dry mouth? |
|
Definition
|
|
Term
| What mAchR receptors does cevimeline show selectivity for? |
|
Definition
|
|
Term
| What metabolizes cevimeline? |
|
Definition
|
|
Term
| Why was atropine formerly used in preanesthetic medication? |
|
Definition
| eliminate the increased secretions associated with their irritant actions |
|
|
Term
| Patient was brought to ER after hallucinations & then collapsing while drinking a gin & tonic prepared by husband. Exam reveals non-responsive 45 yo woman with flushed appearance, dilated pupils, & absence of bowel sounds. What is the source of her intoxication? |
|
Definition
|
|
