Pharmacology of ANS Flashcards
cholinergic receptors
*receive Ach as neurotransmitter
*nicotinic and muscarinic receptors
adrenergic receptors
*receive norepinephrine as neurotransmitter
*alpha (1 + 2) and beta (1, 2, 3) receptors
cholinomimetics
drugs that mimic or augment the action of acetylcholine (parasympathetic agonists)
muscarinic receptors are found on
*organs innervated by PARASYMPATHETIC nerves
*sweat glands (innervated by ACh sympathetic nerves)
*CNS
M2 receptor - location
HEART, nerves, smooth muscle
M3 receptor - location
GLANDS, smooth muscle, endothelium
direct-acting cholinomimetics: MOA
bind and activate muscarinic and/or nicotinic receptors
indirect-acting cholinomimetics - MOA
*inhibits acetylcholinesterase
*result: amplification of endogenous ACh (keeps for ACh around at the receptor)
*note: affect both nicotinic and muscarinic receptors
important direct-acting cholinomimetics to know
1) bethanechol
2) pilocarpine
3) carbachol
4) muscarine-containing mushrooms
bethanechol
*muscarinic agonist (direct-acting cholinomimetic; results in parasympathetic responses)
pilocarpine
*muscarinic agonist, penetrates CNS
(direct-acting cholinomimetic; results in parasympathetic responses)
carbachol
*muscarinic AND nicotinic agonist (direct-acting cholinomimetic; results in parasympathetic responses)
*mostly used as eye drops for GLAUCOMA
important indirect-acting cholinomimetics to know
1) edrophonium (we don’t use this anymore)
2) neostigmine
3) pyridostigmine
4) physostigmine
*also, organophosphates (parathion, sarin)
neostigmine
*indirect acting cholinomimetic
(acetylcholinesterase inhibitor)
*quaternary: poor CNS penetration
pyridostigmine
*indirect acting cholinomimetic (acetylcholinesterase inhibitor)
*quaternary: poor CNS penetration
physostigmine
*indirect acting cholinomimetic
(acetylcholinesterase inhibitor)
*tertiary: better CNS penetration
main difference in effect of indirect-acting cholinomimetics (compared to direct-acting)
act like direct-acting agents, EXCEPT FOR THE VASCULATURE EFFECTS
what cholinomimetic do we use to treat dry mouth
pilocarpine (direct-acting cholinomimetic)
ACh toxicity (organophosphate poisoning) - SLUDGE
Salivation
Lacrimation
Urination
Defecation
GI symptoms
Emesis
(also, constricted pupil, slow heart rate, and bronchospasm)
ACh toxicity (organophosphate poisoning) - DUMBBELSS
Diarrhea
Urination
Miosis
Bronchoconstriction
Bradycardia
Emesis
Lacrimation
Salivation
Sweating
carbamates
*pesticide; reversible AChE inhibitors
what do you treat carbamate toxicity with
atropine (antimuscarinic) alone
what do you treat organophosphate poisoning with
atropine + pralidoxime
anticholinergics
*acetylcholine receptor-blocking drugs
*antimuscarinics are a subtype
*atropine is protype
antimuscarinic drug actions
sedation, mydriasis, cycloplegia (can’t accommodate), dry “sandy” eyes, tachycardia, bronchodilation, decreased respiratory secretions, dry mouth, decreased GI secretions + motility, relaxes smooth muscles of ureters and bladder, slows voiding, suppresses thermoregulatory sweating
important antimuscarinic drugs to know
1) atropine
2) scopolamine
3) ipratropium
4) glycopyrrolate
5) oxybutynin
what antimuscarinic drug is used for asthma and COPD
inhaled ipratropium
what antimuscarinic drug is used for bradycardia
atropine