Local Anesthetics Flashcards
What is the MOA of local anesthetics?
Bind to and block VG Na+ channels-> block action potential
What is the rule of “I’s” for amides/esthers?
Esters have one “I”
Amides have two “I’s”
What anesthetic is only used topically?
Benzocaine
What is the only use of Procaine?
aka Novocain-> used for infiltration anesthesia (i.e. for dental work)
In addition to local anesthesia, what other use does Lidocaine have?
Used as an anti-arrhythmic agent
What side effects do low concentrations of local anesthetics have on the CNS?
Sleepiness, restlessness, light-headedness
What CNS effects can high concentrations of local anesthetics have?
Nystagmus, muscular twitching, convulsions
If a patient is allergic to Procaine, what else will they likely be allergic to?
Other ester drugs-> tetracaine, benzocaine, etc.
Use an amide drug instead
How is cocaine a unique anesthetic?
Has intrinsic vasoconstrictive properties, causes euphoria
What amide anesthetic has a long DOA and can produce prolonged anesthesia?
Bupivicaine
What commonly-used local anesthetic has a medium DOA and is a good choice for people sensitive to esther-type anesthetics?
Lidocaine
What is the primary medical use of cocaine?
As a topical anesthetic of upper respiratory tract
What size nerve does local anesthesia block first?
Small fibers (like type B and C)
If two nerves are the same size, which one will be blocked first by local anesthesia?
The one that is more myelinated (i.e. B fibers are blocked before unmyelinated C fibers)
