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Flashcards in Local Anesthetics Deck (9)
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Key/Most Effective Feature

Block AP


Basic Structure

Hydrophobic Ring + ester/amide linkage + basic amine side chain (so weak bases)


Main Ex.s for Ester and Amide Groups

Cocaine and Lidocaine, respectively


Weak Base Important Features of Cycle

Ionizable w/ pKa ~ 8-9, so prepared at pH of 5-6 so majority will be charged and soluble. Blood/cells = 7.4, so most uncharged. However, you want to buffer to this pH beforehand to establish more base. Uncharged required to cross cell membranes (attack from inside), but charged form required to bind to target


LA Mech

Binds to Vg Na channels (better bc first in AP) by binding "open channel" - use dependence. Have to be in open or inactivated state, so has to be stimulated before will have any effect


Hydrophilic vs. Hydrophobic Pathway

Philic more common, attacks from inside. Phobic attacks laterally


Order Nerves Get Blocked

Smaller (like pain Cs and Adeltas) and myelinated first


Breakdown (2)

Esterases in plasma cleave esters
Amides metabolized in liver so problems for liver pts


2 Side Effects

CNS depression -> respiratory failure or tremors (loss of inhibitory neurons)
Lidocaine is anti-arrythmia