Autonomic Drugs (Cholinergic) Flashcards
Define Cholinergic
Cholinergic agents are compounds which mimic the action of acetylcholine and/or butyrylcholine.
choline is a primary component of the neurotransmitter acetylcholine and functions with inositol as a basic constituent of lecithin.
Choline also prevents fat deposits in the liver and facilitates the movement of fats into cells.
Parasympathetic nervous system uses which Neuro Transmitter to send its messages?
Parasympathetid NS is said to be almost entirely ______…
Provide 5 exmaples
acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic. Ex:
- Neuromuscular junctions,
- preganglionic neurons of the sympathetic nervous system,
- the basal forebrain,
- brain stem complexes ,
- the receptor for the merocrine sweat glands.
Cholinergic affects
decrease HR/AV conduction
Bronchoconstriction/inc. secretions
increase GI/GU
Eye miosis, ciliary muscle contration (near vision)
Direct acting cholinergic drugs:
Action-Name 4
Also known as?
Directly bind to muscarinic receptors
Bethanachol
carbachol
methacholine
Pilocarpine
Known as: Cholinomimetics (direct)
direct acting Nicotinics
name…
Nicotine
Bethanachol: indications
Urinary retention,
postoperative ileus
ACh: indications
Miotic in ophthalmology
Pilocarpine: indications
Treatment of glaucoma
Bethanachol: actions
Stimulates the detrussor muscle and relaxes trigone and sphincter
Bethanachol: Effects of actions
increases voiding pressure and decreases bladder capacity to cause expulsion of urine, lasts a few hours
Bethanachol: Therapeutic application
stimulates atonic bladder mostly in postpartum or postoperative , non obstructive urinary retention, also treats neurogenic atony and megacolon
Bethanachol: Adverse effects
sweating, salivation, flushing, decreased blood pressure, nausea, abdominal pain, diarrhea, and bronchospasm
ACh: actions
decrease in HR and cardiac output, decrease in BP, increase in salivary secrestions, intestinal secresions, GI motility, increases tone of detrusor muscle, enhances bronchiolar secretions, stimulates ciliary muscle contratction, constriction of pupillae sphincter muscle
ACh: therapeutic application
lacks therapeutic importance because of its multiplicity of actions and its rapid inactivation by the cholinesterases
Pilocarpine: Actions
Rapid miosis and contraction of ciliary muscle when applied topically to cornea, one of most potent stimulator of secretions like sweat, tears and saliva, is effective at opening schlemms canal
Pilocarpine: Therapeutic applications
promotes slaivation in patients with xerostomia sjogrens syndrome,used to treat glaucoma and is the drug of choice in the emergency lowering of intraoccular pressure of narrow and wide angle glaucoma. Useful in reversing mydriasis
Pilocarpine: Adverse effects
Because pilocarpine can cross the BBB it can be a poisoning agent causing exaggerated parasympatheic effects like profuse sweating and salivation. Atropine can revers the toxic effects
Name 6
(Indirect-reversible)
Cholinergic Drug
physostigmine
neostigmine
pyridostigmine
edrophonium
rivastigmine
donepezil
Indirect acting cholinergic drugs
ex:
inhibit acetylcholinesterase to allow the accumulation of ACh at all 3 cholinergic receptor sites
Physostigmine, Neostigmine, donepezil
Physostigmine: Action
stimulates muscarinic and nicotinic sites of ANS and nicotinic receptors of the NMJ, it can also penetrate BBB to stimulate cholinergic sites in CNS
Physostigmine: Time duration
lasts about 2-4 hours
Physostigmine: Therapeutic uses
increases intestinal and bladder motility to treat atony of either organ, topically it produces miosis and spasm of accommodation, as well as decreasing intraocular pressure, can be used to treat glaucoma but pilocarpine is more effective.
Physostigmine: Treatment for overdose
used to treat overdoses of drugs with anticholinergic actions like atropine, phenothiazines, and tricyclic antidepressants
Physostigmine: Adverse effects
convulsions (with high doses) bradycardia, fall in cardiac output, paralysis of skeletal muscle
Neostigmine: duration
usually last 30 min to 2 hours
Neostigmine: therapeutic uses
Stim. bladder and GI, treats myasthenia gravis, stimulates a greater # of ACh receptors at muscle endplate
Neostigmine: As an antidote
For tubocurarie and competitive neuromuscular blocking agents
Neostigmine: Adverse effects
salivation, flushing, decreased BP, nausea, abdominal pain, diarrhea, bronchospasm
Neostigmine: contraindications
intestinal or urinary bladder obstruction, pts with peritonitis, or inflammatory bowel disease
Donepezil
an anticholinesterase remedy for the loss of cognitive function in alzheimers patients (alzheimers pts have deficient cholinergic neurons in CNS)
Donepezil: adverse effects
primarily GI distress
Pilodoxene
antidote for indirect cholinergic agonists (reactivates AChE)
name 3
(indirect-irreversible) Cholinergic Drugs
Malathion
parathion
echothiophate
Malathione
(house hold insecticides)
ANS Parasympathomimetic
MOA: Irreversible cholinesterase inhibitor
-tertiary ammonium compound
-binds covalently to esterase enzymes
-not hydrolyzed by esterase enzymes
-rapidly absorbed, multiple sites
- causes SLUD/other ANS things
- CNS disturbance
- not therapeutic
- similar agent as chemical weapon
- atropine is antidote (plus supportive)
Name 3
Ganglionic Blockers
type of drug
hexamethonium
mecamylamine
trimethaphan
Type: Cholinergic Drug
name 1 Depolarizing
NMJ Blocker
Syccinylcholine
Name 6
Non-depolarizing NMJ Blockers
tubocurarine
atracurium
doxacurium
pancuronium
vecuronium
mivacurium
name 1 Nicotinic Blocker
Alpha-Bungarotoxin
name 8 Muscarinic Blockers
atropine
tropicamide
ipratropium
scopolamine
glycopyrrolate
pirenzepine
benztropine
trihexyphenidyl
prevents release of Ach
Botulinus toxin
ACh: actions
decrease in HR and cardiac output, decrease in BP, increase in salivary secrestions, intestinal secresions, GI motility, increases tone of detrusor muscle, enhances bronchiolar secretions, stimulates ciliary muscle contratction, constriction of pupillae sphincter muscle
ACh: therapeutic application
lacks therapeutic importance because of its multiplicity of actions and its rapid inactivation by the cholinesterases
for excessive Ach release
name 2 drugs
latrotoxin
B-bungarotoxin
