All local anesthetics are synthetic analogs of what drug?
What vaso effects do local anesthetics typically have?
They're all vasodilatory; except for cocaine; this activates the sympathetics and tends to be vasoconstrictive.
Local anesthetics are usually weak bases with a pKa of 7.5-.9; what form will their ionizable head group take under body pH?
How do the local anesthetics work?
They bind to voltage gated sodium channels. The cationic head will bind to negatively charge groups on the sodium channel.
The preferentially do this in nerve and muscle membranes.
Which states of the sodium channels bind LAs most readily? Why does this matter?
The opened and inactive states. This means they preferentially bind to cells that are most active.
Name 3 local anesthetics that have an amine group as a linker
Mepivacaine (R= methyl)
Compare Bupivacaine and Lidocaine in their ability to block tachycardias
Bupivacaine is pretty much 90% already at 90bpm. Lidocaine doesn't hit its 50% mark till ~125, making it selective in blocking tachys.
Bupivacaine can be cardiotoxic because it has a higher affinity for close-state sodium channels
Why do we give epi along with most LAs?
Because the actions of the LA is dependent on the [LA] at the nerve. If it escapes into the blood stream it lowers the  and you get more systemic complications.
What type of systemic toxicity can local anesthetics produce when incorrectly injected or absorbed too rapidly? What can be done?
CNS convulsions and depression (leading to respiratory depression). There are no pharmacological antagonists. Instead, give them artifical respiration and administer an anti-convulsant (like valium or another benzodiazepene)
With what drugs do we care about their metabolism?
Lidocaine and Procainamide's (only mentioned on that slide) antiarrhythmic duration of action.
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