Ch.11: Anticholinesterase Drugs Flashcards
anti-cholinesterase agent
drugs that inhibit the enzyme AChE, which degrades Ach. Result is to intensify Ach actions via INDIRECT activation of cholinergic receptors
are anti-cholinesterase agents agonists or antagonists?
NEITHER. They indirectly activate cholinergic receptors
Butyrlcholinesterase (BuChe) fx
(not on list)
hydrolyzes Ach and other esters
unknown physiological role
inhibited by most AChE inhibitors
What happens to BP after administration of AChE inhibitor?
drops
classification of Anti-cholinesterase agents is based on:*
the duration of enzyme inhibitioin by the inhibitor, which is related to the speed with which inhibitor dissociates from the esteratic site of AChE. Chemical structure determines all of this.
rank 3 types of anti-cholinesterase agents in order of shortest to longest acting
quaternary < carbamates < organophosphates
therapeutic uses of reversible anti-AChE agents
- ophthalmic
- GI stimulant
- Diagnostic for myasthenia Gravis
- Anti-parasitic action
How does edrophonium work?
blocks Ach breakdown at neuromuscular jx and promotes Ach stimulation of nicotiic receptors on skeletal muscle. Is a short acting agent
contraindications for use of Anti-AChe agents
- ill or debilitated
- hepatic dz
- resp. dz
- pregnancy
- GI/urinary tract obstruction
- recent exp. to anti-AChE agents
- food or dairy animals
- very young or old
Is edrophonium hydrolyzed by AChE?
NO
How is edrophonium eliminated?
renal excretion (rapid)
therapeutic uses of edrophonium
- temporary reversal of competitive muscle relaxants
- differential diagnosis of myasthenia gravis
Therapeutic uses of neostigmine
-glaucoma
-treat myasthenia gravis
-ruminal or GI stimulant
-reversal agent for muscle relaxants
(anti-parasitic, pupillary constriction)
duration of action of neostigmine
intermediate (1-3 hrs)
does neostigmine cross BBB?
NO
class of neostigmine
reversible anticholinesterase
How is neostigmine eliminated?
hydrolyzed by AChE and pseudo-ChE
class of physostigmine
reversible anticholinesterase
therapeutic uses of physostigmine
similar to neostigmine, but exhibits greater CNS activity
Drugs potentiated by anti-AChE agents**
- succinylcholine
- cocaine
- cholinomimetics
- morphine**
- acepromazine**
- adrenolytic agents
Drugs antagonized by anti-AChE agents**
- atropine
- pancuronium
- glycopyrrolate
- N-butylscopolammonium
drug that antagonizes Anti-AChE agent
quinine
OP-Type acetylcholinesterase inhibitors are used in what setting?
agriculture for pest/rodent control, as nerve gas. Not used clinically
parathion metabolism
metabolized in liver to active form (paraxon)
