1. Cholinergics Flashcards
Cholinomimetics - Available Drugs
Cholinergic Agonists:
- Bethanchol
- Carbechol
- Pilocarpine
- Methacholine
Cholinesterase Inhibitors:
- Neostigmine
- Pyridostigmine
- Edrophonium
- Physostigmine
- Echothiophate
- Donepezil
Cholinergic Agonists - Available Drugs
- Bethanchol
- Carbechol
- Pilocarpine
- Methacholine
Bethanechol - MOA
Cholinergic agonist
- Activate Bowel and Bladder smooth muscle
- Resistant to AChE
“BETHANY, CALL (Bethanechol) me if you want to activate your Bowels and Bladder”
Bethanechol - Clinical Use
Postoperative and neurogenic ileus and urinary retention.
Carbachol - MOA
Cholinergic agonist
- Exact mimic of ACh
“CARBon copy of ACh”
Carbachol - Clinical Use
Glaucoma, pupillary contraction, relief of intraocular pressure
Pilocarpine - MOA
Cholinergic agonist
- Contracts ciliary muscle of eye - open angle
- Contracts pupillary sphincter - narrow angle
- Resistant to AChE
Pilocarpine - Clinical Use
Potent stimulator of sweat, tears, and saliva
“You CRY, DROOL, and SWEAT on your PILOw”
Methacholine - MOA
Cholinergic agonist
- Short acting
- Stimulates muscarinic receptors in the airway then inhaled.
Methacholine - Clinical Use
Challenge test for diagnosis of asthma
Cholinergic Agonists - Toxicities
Exacerbation of COPD, asthma, and peptic ulcers when given to susceptible patients.
Cholinesterase Inhibitors - Available Drugs
- Neostigmine
- Pyridostigmine
- Edrophonium
- Physostigmine
- Echothiophate
- Donepezil
Neostigmine - MOA
Cholinesterase Inhibitor
- Increase endogenous ACh
- No CNS penetration
“NEO (no) CNS penetration”
Neostigmine - Clinical Use
- Postoperative and neurogenic ileus and urinary retention.
- Myasthenia Gravis
- Postoperative reversal of neuromuscular junction blockade
Pyridostigmine - MOA
Cholinesterase inhibitor
- Increase endogenous ACh
- Increase strength
- No CNS penetration
- Long acting
Pyridostigmine - Clinical Use
Myasthenia Gravis
“pyRIDostigmine gets RID of Myasthenia Gravis”
Edrophonium - MOA
Cholinesterase inhibitor
- Increase endogenous ACh
Edrophonium - Clinical Use
Extremely short acting
- Diagnosis of myasthenia Gravis
- Tenselon Test
Physostigmine - MOA
Cholinesterase inhibitor
- Increase endogenous ACh
Physostigmine - Clinical Use
Glaucoma
- Crosses BBB
Atropine overdose
“PHYsostigmine PHYxes atropine overdose”
Echothiophate - MOA
Cholinesterase inhibitor
- Increase endogenous ACh
Echothiophate - Clinical Use
Glaucoma
Donepezil - MOA
Cholinesterase inhibitor
- Increase endogenous ACh
Donepezil - Clinical Use
Alzheimer’s disease
Cholinesterase Inhibitors - Toxicities
Exacerbation of COPD, asthma, and peptic ulcers in susceptible patients.
Poisoning seen with irreversible AChE inhibitors –> Organophosphates - insecticides –> Often seen in farmers
- Diarrhea, Urination, Miosis, Bronchospasm, Bradycardia, Excitation of skeletal muscle and CNS, Lacrimation, Sweating, Salivation.
“DUMBBELSS”
- Antidote is Atropine (ACh antagonist) + Pralidoxime (regenerates AChE)
Muscarinic Antagonists - Available Drugs
Atropine Homatropine Tropicamide Benztropine Scopolamine Ipratropium Oxybutynin Glycopyrrolate Methscopolamine Pirenzepine Propantheline
Muscarinic Antagonists Used on the Eye
Atropine
Homatropine
Tropicamide
Muscarinic Antagonists Used on the Eye - Clinical Use
Produce mydriasis and cycloplegia
Atropine, Homatropine, Tropicamide
Muscarinic Antagonists Used on the Heart
Atropine
Muscarinic Antagonists Used on the Heart - Clinical Use
Treat bradycardia –> Increase HR
Atropine
Muscarinic Antagonists Used on the CNS
Benztropine
Scopolamine
Muscarinic Antagonists Used on the CNS - Clinical Use
Benztropine - Parkinson’s disease
- “PARK my BENZ”
Scopolamine - Motion sickness
Muscarinic Antagonists Used on the Genitourinary System
Oxybutynin
Glycopyrrolate
Muscarinic Antagonists Used on the Genitourinary System - Clinical Use
Reduce urgency in mild cystitis and reduce bladder spasms
Oxybutynin, Glycopyrrolate
Muscarinic Antagonists Used on the Respiratory System
Ipratropium
Muscarinic Antagonists Used on the Respiratory System - Clinical Use
- Asthma
- COPD
(IPRAtropium)
“I PRAy I can breathe soon”
Muscarinic Antagonists Used on the GI System
Methscopolamine
Pirenzepine
Propantheline
Muscarinic Antagonists Used on the GI System - Clinical Use
Peptic ulcer treatment
Methscopolamine, Pirenzepine, Propantheline
Atropine - MOA
Muscarinic antagonist
Atropine - Clinical Use
Antidote for Organophosphate (irreversible AChE inhibitor)(DUMBBELSS) poisoning
- Increase pupil dilation, cycloplegia
- Increase HR
Atropine - Toxicities
- Increase body temp. due to decreased sweating
- Rapid pulse, dry mouth, dry flushed skin, cycloplegia, constipation, disorientation
“Hot as a hare, dry as a bone, red as a beet, blind as a bat, mad as a hatter” - Can cause acute angle closure glaucoma in elderly
- Can cause urinary retention in men with prostatic hyperplasia
- Can cause hyperthermia in infants
