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21 Cards in this Set
- Front
- Back
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Drugs that mess with Ach biosynthesis and release? (3)
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Hemicholinium (HC-3) - blocks Choline trans into Nerve
Vesamicol - blocks Ach packaging into vesicles Botulinus Toxin From Clostridium botulinum blocks vesicle fusion at terminal (cleaves Synaptobrevin) Death by Flaccid Paralysis 1 of most potent toxins - 3 micrograms will kill a human |
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Synthetic Parasympathomimetic Drugs (4)
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Acetylcholine (not used)
Metacholine (Musc, Brady/HypoBP) Carbamylcholine / 'Cabachol' (Musc and Nic - Glaucoma Tx) Bethanecol / Myotonachol (Musc - test Panc, Tx urinary retention) |
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Naturally Occurring Parasympathomimetic Drugs (3)
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Pilocarpine
Arecoline Muscarine |
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Pilocarpine
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Pilocarpus shrub
100x Ach potency MUSCARINIC > nicotinic Increases Salivation and Sweating *Stims Miosis ----> lower IO pressure ~may cause tachycardia/hypertension |
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Arecoline
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from Betel Nut of Areca catechu
Muscarinic AND Nicotinic ~addictive/stimulant like Nicotine *Not currently used (was a vermifuge, is a taenicide in China) |
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Muscarine
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from Amantia muscarina mushrooms
MUSHROOM POISIONING: SLUD, GI Pain, CV Collpase, vertigo-confusion-coma-DEATH onset under 1 hour - Death w/in hours *Antidote = ATROPINE |
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Anti-Muscarinic Agents (5)
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Homoatropine (fast/less potent)
Scopolamine (Tx Motion Sickness) Propantheline (no BBB, decrease spasm - Tx diarrhea or choke) Tropicamide aka Mydriacil - (short acting mydriasis) Atropine |
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Atropine
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from Deadly Nightshade (Atropa belladona)
competitive Muscarinic ^HR, bronchoDilate, v-resp secretions, v-GI motile, MYDRIASIS Tx - Pre-Op Med, AntiAsthmatic, OTC Lacrimal/Nasal Glands |
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Glaucoma Tx
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Muscarinic Agonists
(miosis -> ^drainage -> low IO press) B-Blockers - TIMOLOL - decrease aq. humor production |
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Nicotinic Ganglionic Agonists (4)
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Lobeline (Lobelia - the patch, the gum)
DMPP (3x Nicotine potency, always on) TMA (always on - no dose dep. off) NICOTINE complex, unpredictable - high doses may INHIBIT N-R's. Effects at Nn (ganglionic) therefore hits SYMP and PARASYMP - who knows what will happen!? |
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Nicotinic Ganglionic Blockers (2)
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Trimethaphan (Vet Med - Lower BP in Sx)
Hexamethonium aka C6 Ganglionic blocker, therefore blocks both SYMP and PARASYMP... therefore very limited uses. |
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3 Classes of Anti-AchE
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1. Reversible - N binds Anionic AchE site temporarily
2. Carbamylating - substrate binds Active AchE site for extended period 3. Phosphorylation of AchE - Covalent bind, IRREVERSIBLE inactivation of AchE enzyme) |
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Reversible Anti-AchE Drug (1)
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Edrophonium aka Tensilon
M.Gravis - Immune Mediated Ach-R defect Tx M.Gravis - Transient Improvement Tx Cholinergic Crisis - Transient Worsening |
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Carbamylating Anti-AchE Drugs (5)
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Physostigmine aka Eserine
Neostigmine aka Prostigmin Pyridostigmine Demeserium Carbaril aka Sevin |
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1. Eserine / Physostigmine
2. .Prostigmin / Neostigmine 3. Pyridostsimgine 4. Demeserium 5. Carbaril / Sevin |
1. well absorbed, x-BBB (Glaucoma, Atropine poisoning)
2. not well absorbed, no x-BBB (M.Gravis) 3. shorter half life (nerve gas prophylactic) 4. more potent, longer duration 5. Insecticide |
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Phosphorylating Anti-AchE Drugs (4)
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1. DFP - must make new AchE to recover
profound toxic effects - cumulative over reasonable amt time 2. Sarin (GB) - quick, less persistent 3. VX - more toxic, very persistent, normally liquid form which can stick 4. OrganoPhosphates - insecticides |
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What will Nerve Gas or OrganoPhosphate insecticides do to you?
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Irreversibly bind your AchE... therefore you will not break down your Ach.
Initially - Increase Ach --> muscle twitching --> fasciculations ...Eventually, you exhaust your Ach (no recycling) and your Ach-R's --> Paralysis and Death |
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How do you defend yourself from that Nerve Gas?
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2 ways... 1. Pyridostigmine
2. Inject yourself with Pralidoxime (2-PAM) and Atropine Pralidoxime will dephosphorlyate and thus RECOVER AchE Atropine will block Ach-R's at MUSCARINIC sites, therefore protecting you against overflow of Ach |
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NEUROMUSCULAR BLOCKERS
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ie - No Longer Parasympathetic ANS
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Competitive Blockers at NMJ (3)
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CURARE - Arrow Poison
d-Tubocuranine Pancuronium (Pavulon) Atracurium (Tracrium) short onset, long acting, no x-BBB **RECOVER w/ Anti-AchE |
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Depolarizing Blockers at NMJ (1)
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Succinylcholine (Anectine)
ultra short onset, short duration (longer in dog than other animals) Desensitizes Ach-R's at NMJ *NO RECOVERY - just time |
