Cholinergic Drugs Flashcards
Atropine SEs
Atropine flush: cutaneous vasodilation
Anti-PANS: dry mouth, blurred vision, dry eyes, tachycardia, constipation
CNS: restless, confusion, hallucination, delirium, depression
Parathion
Chem: organophosphate
Metabolism: phosphorylation enzyme, hydrolyzes v slowly
Risk: farmers
(More dangerous of the 2)
Carbachol
Chem: choline ester
Target: nicotenic and muscarinic
Metabolism: resistant to hydrolysis by AChE
Use: miosis during surgery, dec IOP s/p cataract surgery
Ipratropium and Tiotropium
Chem: wuarternary ammonium muscarinic antagonist
Use: tx COPD and asthma
Pyridostigmine
Chem: carbamate / quaternary ammonium (No CNS)
Metabolism: covalent bond formed w/ enzyme
Use: treats Myasthenia Gravis (most common)
Physostigmine
Chem: carbamate / tertiary amine (= CNS entry)
Metabolism: covalent bond formed w/ enzyme
Use: tx of OD w/ anticholinergic drugs (i.e. - Atropine)
SE: can aggravate depression of cardiac conduction in pt w/ suspected TCA (tricyclic antidepressant) overdose; convulsions, bradycardia
Tolterodine
Use: overactive bladder
Atropine
Chem: tertiary amine (effects CNS)
Mechanism: competitive binding to muscarinic receptors preventing ACh from binding
Methacholine
Chem: choline ester Target: mainly muscarinic Metabolism: resistant to hydrolysis (slowly hydrolyzed by AChE) Uses: dx asthma SE: exacerbation of asthma/COPD
Tubocurarine
Chem: nondepolarizing NM blocker
Mechanism: competitive antagonist
Use: adjuvant in anesthesia during surgery to relax skeletal muscle
Vesamicol
Mechanism: blocks vesicular ACh-H+ antiporter (VAChT) to prevent storage of ACh invesicles
Use: research
Rivastigmine
MOA: AChE inhibitor
Use: Alzheimer’s Dz and Parkinson’s dementia
SE: AV block
Tabun, Sarin, Soman
Chem: synthetic toxic nerve agents
Use: toxic poison
Homatropine, Cyclopentolate, Tropicamide
Use: produce mydriasis w/ cycloplegia for ophthalmologist exams
(Preferred to atropine bc of shorter duration of action)
Hemicholinium-3
MOA: blocks choline transporter (CHT1) pre-synaptically to prevent synthesis of ACh
Use: research
Hexamethonium, Mecamylamine, Trimethaphan
Chem: ganglion blockers (nicotenic antagonist)
Use: (not used now) were once used to tx HTN but had too many SEs
Pilocarpine
Chem: tertiary amine MOA: partial muscarinic agonist Metabolism: stable to hydrolysis by AChE Use: 2° for open angle glaucoma, acute angle-closure glaucoma, dry mouth d/t radiation or Sjogren's SE: CNS disturbances
Atropine Uses
- Antisialogogue: before surgery to decrease resp secretions
- HR: to increase HR or decrease AV-block
- Antidote for OD of cholinergic drugs
- Antidote for muscarine poisoning 🍄
- Alleviate muscarinic SEs from AChE inhibitors
Atropine Effects
Eye: mydriasis, cycloplegia (focus for distance)
GI: decreased gut tone and motility
GU: decreases bladder motility
CV (low dose): bradycardia d/t pre-synaptic M2 receptor blockade
CV (mod to high dose): tachycardia
Nicotine
Chem: tertiary amine
Target: NMJ
Low doses: ganglionic stimulation by depolarization (PANS + SANS is what it resembles)
High doses: ganglionic blockade and NM blockade
Uses: smoking cessation therapy
Botulinum Toxin
MOA: inhibits ACh release from pre-synaptic neuron
Use: locally in muscles for dz w/ muscle spasms, cosmetic tx of wrinkles
Scopolamine
Use: prevents motion sickness; also used in anesthetic procedures to block short-term memory
Glycopyrolate
Use (PO): inhibit GI motility
Use (IV): prevent bradycardia during surgery
Atropine Metabolism
Rapidly absorbed, partially metabolized by liver, elimination via urine
t1/2 = 4h
Succinylcholine
Chem: depolarizing NM blocker
MOA: binds nicotenic receptor and depolarizers the NMJ stimulating the receptor - eventually receptor desensitization
Use: flaccid paralysis for intubation, or ECT
SE: malignant hyperthermia d/t excessive Ca2+ release (tx w/ Dantrolene)
Bethanechol
Chem: choline ester
Target: mainly muscarinic
Metabolism: resistant to hydrolysis by AChE
Uses: post-op/post-partum urine retention, atonic bladder
SE: sweating, flushing, salivation, diarrhea, nausea, abd pn, hypotension, bronchospasm
Benztropine and Trihexyphenidyl
Use: tx Parkinson’s dz and extrapyramidal effects of antipsychotic drugs
Neostigmine
Chem: carbamate / quaternary ammonium (NO CNS)
Metabolism: covalent bond formed w/ enzyme
Use: reversal of non-depolarizing NM blockers s/p surgery; prevention and tx of post-op distention and urinary retention, tx Myasthenia Gravis
Echothiophate
Chem: organophosphate
Metabolism: phosphorylation enzyme, hydrolyzes v slowly
Use: chronic open-angle glaucoma, subacute or chronic angle-closure glaucoma
Malathion
Chem: organophosphate
Metabolism: phosphorylation enzyme, hydrolyzes v slowly
Risk: farmers
(Rapidly metabolized so less dangerous)
Edrophonium
Chem: quaternary ammonium (no CNS)
Metabolism: short-lived d/t reversible binding to active site of enzyme (no covalent bond)
Use: dx Myasthenia Gravis, reverse the effects of non-depolarizing muscular blockers
Muscarine
Chem: alkaloid
Target: muscarinic
Pralidoxime
MOA: reactivation of inhibited AChE
Use: tx of organophosphate insecticide poisoning
Arecoline
Chem: natural alkaloid
Target: muscarinic and nicotenic
Donepezil
MOA: AChE inhibitor
Use: Alzheimer’s Dz
SE: AV block
Acetylcholine
Chem: choline ester
Metabolism: rapidly hydrolyzed by AChE
Uses: to obtain rapid miosis after cataract surgery
