Anticholinesterase Antagonists Flashcards
RVC drugs
Edrophonium
Donepezil
RC drugs
Neostigminee
Physostigmine
IC drugs
Malathion
Edrophonium uses
Diagnosis MG
Tensilon test: distinguish myasthenic crisis from cholinergic crisis
SE of edrophonium
Only improves myasthenic symptoms
Worsens cholinergic crisis (desensitization, flaccid paralysis)
MOA edrophonium
- Quat ammonium
- bound AChE by weak H and ionic bonds
Does NOT cross BBB Short Doa (5-10 mint)
Donepezil MOA
Lipid soluble
Can cross BBB
Use of donepezil
Cognitive decline in AD
Increase cognition, but NOT disease progression
SE donepezil
Mild diarrhea
N/V
Bradycardia
MOA neostigmine
- quat ammonium
- some lipid solubility
- bound to AChE by ionic and reversible covalent bonds
DOA 2 hours
- does NOT cross BBB
What is the only inhibitor that is also an agonist at NMJ N receptors??
Neostigmine
Low neostigmine doses
Increase force of contraction
Therapeutic
High doses of neostigmine
Decrease force of contraction (desensitization)
Toxic
Neostigmine use
MG therapy
Postop urinary retention
Reverse competitive neuromusclar blockade after surgery
SE of neostigmine
Excessive M stimulation (N/V, GI cramping, bradycardia) d
Neuromusclar blockade: paralysis of diaphragm at toxic doses
What can neostigmine be treated with?
Atropine
Physostigmine MOA
Crosses BBB
Not direct cholinergic agonist
Use of physostigmine
Treat poisoning by atropine & related drugs that block M blockade
Reverses both peripheral & CNS effects
SE of physostigmine
Blurred vision
Photophobia
Increase IOP
Malathion MOA
DOA >50h
Prodrug converted to active
Highly toxic metabolite
OP insecticides
Use of malathion
Head lice
SE malathion
Common source of accidental and agricultural poisoning
Pralidoxime MOA
Must be administered before aging occurs
Use of pralidoxime
Reactivates AChE ONLY at neuromuscular junction
