Local Anesthetics

Question 1

Amides?

Answer 1

Lidocaine, bupivacaine, and ropivacaine.

Question 2

Amides and esters: MOA

Answer 2

Local anesthetics target voltage-gated sodium channels which are responsible for upstroke of action potential. These agents bind to site within channel itself rendering it impermeable to sodium ions.

Question 3

Amides and esters: Indications

Answer 3

Local anesthetic temporarily blocks propagation of action potentials along nerve fibers to render a specific site insensitive to noxious stimuli. Molecules that belong in this category have similar MOAs, chemical structures, and side effect profiles.

Question 4

Amides and esters: Side effects

Answer 4

Hypersensitivity reaction: Allergic responses are more common with esters secondary to one of their metabolic products (para-aminobenzoic acid or PABA).

Perioral numbness

Seizures

Question 5

Esters?

Answer 5

Benzocaine, procaine, tetracaine, cocaine