Local anesthestics (must know) Flashcards
Basics of how LA work
the non-ionized portion rapidly goes into the cell once inside it binds with the H+ and becomes ionized to maintain equilibrium with extracellular ionized forms, then only the ionized form can bind to the receptor
3 parts of local anesthetics structure
Lipophillic group (aromatic)- amide or ester link Hydrophillic group (Amine)
How to identify an amide or ester LA by looking at it
-1st look for the carbonyl carbon (carbon double bonded to oxygen)
-next look to Right or Left to determine amide or ester
amide -N
ester -O
Explain & identify N-dealkylation
an enzyme detaches one or more carbons atoms from the Amine group, making it either 2 or 1 degree amine
–the target is the amine group
Explain Aromatic hydroxylation
Introduction of an OH (hydroxyl) to the benzene ring
–target is the lipophillic group (aromatic)
Explain aminde hydrolysis
an enzyme breaks down H20 into H and OH then the OH replaces the N group in the Amide
Chirally
an object that cannont be superimposed on its mirror image
Enantiomer
2 mirror image forms of a chiral molecule, same formula but different arrangement of molecules
Weak bases become what in acidic enviroments
Ionized
Ionized drugs are more soluable where
H20
Weak bases are prepared in what?
Weak Acids are prepared in what?
- –Acids
- -basic
What are anesthetics Ionized or unionized
both
What part of LA crosses membrane
non ionized
Which part of LA binds to Na+ channel?
ionized
why is it important to know that LA receptor sites are proteins?
B/c the higher affinity for protein, the longer the LA will last
*** not always about the plasma proteins!!!
