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43 Cards in this Set
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Physostigmine gen
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Physostigmine gen:
- cholinesterase inhibitor - tertiary amine, hydrolyzed by plasma esterases - crosses blood-brain barrier - miosis, salivation, inc GI motility - large doses: skeletal m fasiculation, followed by paralysis - not commonly used |
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physostigmine therapeutic use
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physostigmine therapeutic use:
- topical tx: simple, secondary glaucoma - IM, SQ or PO: counteract atropine, muscarinic drug intoxication |
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neostigmine gen
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neostigmine:
- cholinesterase inhibitor - tertiary amine, hydrolyzed by plasma esterases - does not cross b-b barrier - |
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neostigmine action
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neostigmine action:
- inhibits AChE, inc ACh from nerve endings - acts directly on skeletal neuromuscular jxn |
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neostigmine therapeutic use
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neostigmine therapeutic use:
1. reversal of neuromuscular blockers 2. paralytic ileus 3. atony of u bladder 4. myasthenia gravis-like conditions - contraindication: GI and urinary obstruction - duration: 0.5- 2 hrs |
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edrophonium
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edrophonium (tensilon):
- cholinesterase inhibitor - quaternary ammonium comp'd - action like neostigmine - dx of myasthenia gravis-like dz - antagonize tubocurarine-like drugs |
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pyridostigmine and demercarium
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pyridostigmine (mestinon) and demercarium:
- cholinesterase inhibitors - similar to physostigmine and neostigmine - longer action: 4-6 hrs - dem: topical glaucoma tx |
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carbaryl and propoxur
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carbaryl and propoxur:
- carbamate anti-cholinesterase - flea control (ectoparasiticides) - overdose similar to organophosphate poisoning, tx atropine |
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ecthiophate
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ecthiophate:
- quaternary organophosphate - long action > 12hr - topically: tx open angel glaucoma - ectoparasitacides |
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dichlorvos
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dichlorvos:
- organophosphate - anti-helmintic and pesticide |
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organophosphates
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organophosphates:
1. ecthiopate 2. diisopropyl fluorophosphate (DFP) 3. tetraethylpyrophosphate (TEPP) 4. parathion, malathion 5. soman, tabun, sarin: nerve gases 6. dichlorvos |
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organophosphate signs
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organophosphate signs:
1. salivation, lacrimation 2. urination, defecation 3. dyspnea 4. miosis 5. bradycardia 6. anorexia, vomiting |
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organophosphate neuro signs
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organophosphate neuro signs:
1. convulsion 2. skeletal m fasiculation 3. respiratory failure: inhibition of respiratory center in medulla, bronchial spasm - death due to respiratory arrest |
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organophosphate tx
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organophosphate tx:
1. detox: dermal, oral exposure 2. stabilization: anticonvulsants, respiratory support - doxapram/ dopram: universal respiratory stim 3. antidote: - atropine: counteracts symptoms, doesn't reactivate AChE - pyridine-2-aldoxime methiodide (2-PAM): reactivates AChE |
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PS antagonists/ parasympathetolytic agents
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PS antagonists/ parasympathetolytic agents:
1. atropine 2. glycopyrrolate 3. scopolamine (hyoscine) 4. propantheline 5. tropicamide 6. pirenzepine 7. aminopentamide (centrine) |
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Atropine gen
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Atropine gen:
- PS antagonist: anti-muscarinic - tertiary amine - competitive, non-selective (acts in heart, lung, etc) of Ach at muscarinic receptors - |
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atropine effects
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atropine effects:
1. heart: SA node= tachycardia 2. CNS: toxic dose= excitation followed by depression 3. smooth m: dec GI amplitude and freq of contraction, bronchodilator 4. eye: mydriasis, blocks sphincter of iris, cycloplegia (inability to accomodate for near vision), inhibits cholingeric control of ciliary mm of lens |
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atropine therapy
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atropine therapy:
1. preanesthetic: dec salivary and resp secretion - not in horse, R because slows down GI, thickens saliva which can cause choking 2. opthamology 3. renal and biliary colic 4. counter effects of anti-AChE drugs: neostigmine, thysostigmine |
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atropine HL
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atropine HL:
- 2.5 hrs - most excreted in urine w/i 12 hrs |
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atropine adverse effects
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atropine adverse effects:
1. tachycardia 2. photophobia 3. inc body T 4. restlessness 5. disorientation and CNS stim |
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atropine toxicity
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atropine toxicity:
1. neostigmine. physostigmine 2. control CNS stim with benzodiazepines |
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glycopyrrolate (robinul)
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glycopyrrolate (robinul):
- PS antagonist (anti-muscarinic) - synthetic quarternary ammonium compound - preanesthetic IV, IM, SQ - doesn't enter CNS or eye - effects longer than atropine: 2-3 hrs, antisalivation up to 7 hrs - elimination primarily by kidney, not metabolism |
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scopolamine (hyocine) and N-butylscopolammonium (bucospan)
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scopolamine (hyocine) and N-butylscopolammonium (bucospan):
- PS antagonists, anti-muscarinic - resemble atropine - crosses B-B barrier - control motion sickness - Bucospan: Eq IV as anti-spamodic in colic, intestinal impaction - cause excitation or sedation |
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propantheline
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propantheline:
- PS antagonist (anti-muscarinic) - small animal anti-spasmodic, diarrhea tx - eq: relaxes for rectal exam to prevent injury |
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tropicamide
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tropicamide:
- PS antagonist (anti-muscarinic) - shorter duration - opthalmology |
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pirenzepine
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pirenzepine:
- PS antagonist (anti-muscarinic) - dec gastric acid secretion |
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autonomic ganglionic agonists
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autonomic ganglionic agonists:
1. nicotine: nicotinic receptor 2. anti-nematodal: levamisole, pyrantel, morantel - activate nicotinic in S and PS ganglia: stimulate post-ganglionic neurons - mimic ACh action |
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autonomic ganglionic antagonists
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autonomic ganglionic antagonists:
- act at post-ganglionic nicotinic: blocks S and PS transmission 1. hexamethonium 2. trimethaphan 3. mecamylamine |
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cholinergic agonists
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cholinergic agonists:
1. choline 2. acetylcholine 3. methacholine: acetyl-b-methylcholine 4. carbachol: carbamylcholine 5. bethanecol 6. plant alkaloids: pilocarpine, aerocholine, muscarine |
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cholinergic smooth m, gland effects
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cholinergic smooth mm and gland effects:
- stim M3 1. inc GI motility, secretion 2. smooth m contraction: uterus, ureters, bladder, bronchi and sphincter of iris mm 3. bronchial constriction 4. inc salivary, lacrimal gland secretion |
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cholinergic CNS effects
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cholinergic CNS effects:
- musc and nico in CNS - ACh in circulation: no effect as lipophobic and poorly penetrates B-B barrier |
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cholinergic cardio effects
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cholinergic cardio effects:
- similar to vagal stim: 1. - inotropic 2. - chronotropic 3. vasodilation: most peripheral vessels not cholinergically innervated so little control of BP - some ACh analogs inhibit release of NE from S end nerve terminal by activating M2 receptors on endothelial cells: NO release causing vasodilation |
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ACh effects on other systems
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ACh effects on other systems:
- little use in therapy except topical to constrict pupil in ocular sx - atropine: muscarinic antagonist - somatic NM jxn |
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drug effects of cholinergic agents
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drug effects of cholinergic agents:
SLUDGE 1. Salivation 2. Lacrimation 3. Urination, urinary incontinence 5. Diarrhea 6. GI cramps 7. Emesis |
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drug effects of cholinergic agents
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drug effects of cholinergic agents:
1. stim intestine: secretion, motility 2. stim bladder: inc urine freq 3. stim pupil: miosis (constriction), dec intraocular P |
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cholinergic rx
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cholinergic rx:
synthetic choline ester compounds that act similar to ACh: 1. methacholine - more active in GI than cardio 2. carbachol 3. bethanecol |
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carbachol
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carbachol:
- cholinergic agonist - quarternary N compound with carbamic acid ester bond not hydrolyzed by AChE - activates M and N |
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carbachol therapy
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carbachol therapy:
1. topical producing miosis 2. SQ: tx GI, rumen or uterine atony, impaction - use w/ caution to prevent rupture of tracts |
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bethanechol
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bethanechol:
- muscarinic agonist - resembles carbachol: quarternary N compound resistant to AChE hydrolysis |
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bethanechol therapy
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bethanechol therapy:
1. SQ tx for bladder distention: inc contractility 2. GI and uterine atony: caution as may cause rupture - no GI abs |
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pilocarpine
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pilocarpine:
- cholinergic agent: primarly M - tertiary amine alkaloid - doesn't cross cell mem - arecoline similar action |
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pilocarpine therapy
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pilocarpine therapy:
1. glaucoma: dec intraocular P 2. like ACh: stim exocrine galnds, saliva, mucous, gastric/ dig/ pancreatic secretions |
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anti-cholinesterase agent
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anti-cholinesterase agents:
1. reversible: physostigmine, edrophonium, pyridostigmine 2. irreversible: organophosphates eg diisopropyl fluorophosphate (DFP) |