Cholinergic and Anticholinergic Flashcards
Gimme the NT involved and the Muscarinic stuffies
2 systems, 1 system, 5 systems
All pre G is Ach, Nicotinic
- Post G parasympathetic is all Muscarinic, including Sweat Glands; under sympathetic control
- NMJ, somatic is NICOTINIC
M1
- N&V, Vomiting Centre, Vestibular Nu
- CNS Confusion, Delirium also
- Note Vestibular & VC has H1 and mAch
- Stomach Acid secretion
M2
- Heart
M3
- Lung, Secretion
- Saliva, GI secretion
- GI motility
- GU, bladder contraction, erection
- EYE - near vision, iris sphincter, lens thickening, ciliary muscle - all improves drainage, decreases IOP, good for glaucoma
- SWEAT
Hence should Ach overdose what are the effects in general
Parasympathetic - diarrhoea, urine, near vision; Nausea Vomiting
Sympathetic - sweat
SOMATIC motor - fasciculation, spasms, falccid paralysis
Excitation of skeletal muscle and CNS!!!
What is contra-indicated for Ach agonists
Asthma; COPD
- M3 bronchoconstriction
Peptic ulcer disease
- M1 stomach secretion; recall Vagus, parietal
acute asthma, myocardial infarction, hyperthyroidism, paralytic ileus, benign prostatic hyperplasia, urinary retention, narrow-angle glaucoma, and myasthenia gravis.
In open-angle (WIDE) glaucoma, the iris is in the right position, and the uveoscleral drainage canals are clear. But the trabecular meshwork isn’t draining properly. In closed-angle (NARROW) glaucoma, the iris is squeezed against the cornea, blocking the uveoscleral drains and the trabecular meshwork.
Muscarinic Agonists 2 names and functions
- side effects?
Pilocarpine and Bethanechol
- both are non selective
Pilocarpine focus on SALIVA and eye functions
- miosis, accommodation, improve IOP - Glaucoma
- saliva for dry mouth
Bethanechol - think GI, GU
- GI motility for gastric atony after vagotomy
- GU for peeing for urinary incontinence
AE:
- Respi: COPD, Asthma
- Sweat
- GI,
- N&V
- Ophthalmic - miosis, near vision
Nicotine low dose function
USE
AE
Note nicotine receptors at Pre-G also for Sympathetic
++++ NMJ hence: activating
CVS: BP increase, RR increase; Vasoconstriction
GI: motility increase
NMJ: fasciculations
CNS: N&V
USE: Smoking cessation
AE: Dependence
Indirect cholinergics! what class and names only
AchE Inhibitors - just either reversible or irreversible
Reversible
- Neostigmine
- Physostigmine
- DONEpezil
Irreversible
- Sarin
Reversible AchE inhibitors clinical functions
AE
Donepezil - Azh Disease (Cholinergic neurons affected)
Neostigmine - NMJ for Myasthenia Gravis
- reversal of NM blockage after surgery;
- urinary retention treatment
AE
- Bradycardia, hypotension
- miosis, ab cramp
Whats sarin;
effects
antidote
Organophosphate; suicide AchE Inhibitor
- Bradycardia
- RR depressant;
- Sweat
- diarrhoea
- blurry vision
- N&V; Coma;
NOTE ACH is also universAL to nicotine to NMJ
- but sympathetic “dominance” is not here
- NMJ: Fasciculation, spasms, flaccid paralysis
Antidote
- Pralidoxime
- removes phosphate before ageing
- regenerates AchE
- Also Atropine
- block parasymp functions
- mAch blocker
Atropine
effects
use
contra I
Effects
- Confusion, Delirium (hence crosses BBB)
- M1: gastric secretion
- M2: CVS INCREASE
- M3: GI decrease GU decrease, sweating decrease; Eye dilated - mydriasis - careful increased IOP
- Blind, Mad, Hot, Red, Dry
- — red could be TC + CUTANEOUS Vasodilation
Use:
- bradycardia
- ophthalmic exams
- AchEI overdose
- Diphenoxylate opioid diarrhoe, prevent abuse;
contra I is Glaucoma;
note Benztropine for Parkinsonism
- cos DoR blocked
- Ach control
okie
Hyoscine, Scopolamine
functions
gimme a related drug
N&V
- block M1 in Vomiting centre, more impt in
- Vestibular Nu - for motion sickness
Diphenhydramine - first gen AH
- combined H1 blocker + M blocker
- both H1 and M1 are found at Vestibular Nu for motion sickness;
- but this one has sedation cos first gen AH
Ipratropium use
- SSSSAMA
Muscarinic antagonist
- Lung bronchoconstriction and secretions for COPD
- first line COPD second line Asthma
Note Scopolamine crosses BBB for N&V
- Atropine crosses BBB for delirium, confusion AE
- Ipratropium does not
okie
Nicotinic high dose
MOA
Effect
Depolarizing ganglionic block
Depolarizes cell, the VGNC inactivated
cell repolarizes but desensitized to action potential
Effect:
- block - respi block, BC, NM block
2 stages are depolarizing blockage and non-depolarizing blockage
NM blockages
- think of function why block NMJ
Non-depolarising NMBA, blocking agent
- pancuronium
- NMJ block
- used for surgery
- can be overcome w AchEI
DNMBA
- succinylcholine
- cannot be overcome w AchEI
- Phase 1: depolarises cell, fasciculations
- Phase 2: cell repolarizes but desensitized
- used for surgery
Botininum Toxin
- cleaves SNARE protein needed for exocytosis of Ach at NMJ
- AE: allergy, wrong paralysis
