Chapter 7-8: Indirect Acting Cholinomimetics Flashcards
Test 2
Describe Indirect acting Cholinomimetics
block acetylcholinesterase
Name the 3 types of Indirect acting Cholinomimetics
- Simple Alcohols: Edrophonium
- Carbamic acid esters of alcohol: Carbamates and -stigmine
- Organic derivatives of phosphoric acid: organophosphate
T/F: Simple acids lasts for a long time
F
Short time
Describe Organophosphates
Last for long time
can form covalent bonds
What medication is used for MG Dx testing?
What is the DOA?
Edrophonium (Simple alcohol)
5-15 mins
What 2 drugs treat MG? What is the DOA?
Neostigmine - 0.5-2 hrs
Pyridostigmine - 3-6 hrs
What is the Tx for Glaucoma? DOA? Classification?
Echothiophate
100 hours
Organophosphate
How fast do Indirect acting Cholinomimetics work?
150 mircoseconds
Organophosphate form _______ bonds in the active site with _______
Covalent
Phosphorous
What drug can break the covalent bond with organophosphates?
Pralidoxime
If given within the 1st few hours
Explain the MG diagnostic testing process
2mg IV Edrophonium - watch for negative side effect
8mg IV - watch for improvement to see if other Indirect acting Cholinomimetics will work
What are side effects of direct acting muscarinic overdose?
(-ine, choline esters, colorful mushrooms)
SLUDGEM!!!!!!
What is SLUDGEM
Salivation
Lacrimation
Urination
Defication
GI motility
Emesis
Miosis
What is the Tx for direct acting muscarinic SLUDGEM symptoms?
ATROPINE
or Pralidoxime
Describe Toxicity in direct acting nicotinic stimulants
40mg is fatal
Want to induce vomiting
usually child eating cigarettes
S/S: HA, N/V, Dizziness, Breathlessness, Collapse, LOC
What is a Cholinoceptor Blocking agent?
Cholinergic receptor blockers:
Antimuscarinic/Antinicotinic
or muscarinic/nicotinic antagonist
Blocks effects of natural ligands of the SNS and PNS at these receptors
What is the Amanita phalloides?
“Deadly nightcap”
Noncolorful mushroom
inhibits mRNA synthesis
causes death within 4-7 days
What is the antimuscarinic prototype?
Atropine
Describe Atropine
Antimuscarinic
Plant based alkaloid
Racemic mixture of D and L
In racemic atropine, the L isomer is ______ times more potent than the D isomer
100x
What does belladonna mean?
Beautiful woman
What does atropine or another plant based alkaloid do to the pupils?
dilate
Describe Scopolamine
Antimuscarinic
Tx of motion sickness
very lipid soluble (patch)
Similar to atropine but shorter DOA
Indications for antimuscarinics
block overproduction of PNS
What is Atrovent
inhalant antimuscarinic – bronchodilating effects
Tx of asthma/COPD bronchospasms
What is Cycloplegia?
Happens when you take a med that dilates your pupils
Paralysis of ciliary muscle
attaches to ciliary cords that hold lense in place and cant switch from near/far vision (accommodation)
Dont drive
What drug is used by the eye doctor to dilate the pupils? DOA?
Tropicamide
4-6 hrs
Summary of atropine effects: urine, HR, Eye, Salivation
Urine: decrease
HR: increase
Eye accommodation: decrease
Salivation: decrease
Contraindications for antimuscarinics
Glaucoma (open/closed)
Elderly men (d/t BPH)
Muscle relaxants =
Neuromuscular blocking drugs
Where and how do muscle relaxants work?
Block nAch-R at the NMJ skeletal muscle end plate
describe ion flow in nAch-R
Na+ floods in
Ca++ slowly comes in
K+ comes out
What is Succinylcholine?
Depolarizing muscle relaxant
contracts onces, then relaxes and stays there
wont repolarize
Nondepolarizing muscle relaxants are ________derivatives
curare
How does non depolarizing muscle relaxants work?
by outcompeting Ach and blocking the actual channel
1 alpha subunit only needs to be blocked
Depolarizing muscle relaxant clinical use and name:
Succs
Intubation
Succs side effects (important ones only)
Hyperkalemia
MH
Apnea
Name a few nondepolarizing muscle relaxants
Pancuronium - long acting
Atracurium - intermediate
Mivacurium - short
Name 2 neuromuscular blockers reversals
Sugammadex
Neostigmine
