13

Question 1

Postitively charged anesthetic will

Answer 1

act once it gets inside neural membrane. Both form of anesthetics exist, and amine groups help get pKa to 7.4 where we want these to be working.

**basic form does a better job of getting in the membrane than acidic form generally speaking. Both act, but the basic form gets in better.

Question 2

Ester linkages ——- better than amide

Answer 2

break apart - serum cholinesterases will hydrolyze esters

Question 3

Aromatic groups are for

Answer 3

lipophilic properties - crossing membranes.

Question 4

Do NOT inject these things into

Answer 4

arteries - they will get into the brain.

Question 5

Esters downsides

Answer 5

hydrolyzing leads to something being more allergenic - the hydrophobic group is allergenic.

Question 6

Local anesthetics with an ester linkage will be hydrolyzed by

Answer 6

pseudocholinesterase and have a very short half life in the plasma

Question 7

Local anesthetics with an amide linkage will be metabolized by

Answer 7

P450 enzymes in the liver and have a longer half life in the plasma.

Question 8

Esters are more generally

Answer 8

allergenic

Question 9

Amides will have an

Answer 9

I in their name prior to the “caine”

Question 10

Local anesthetics favored in dentistry are

Answer 10

amides

Question 11

Local anesthetics cross the axon membrane and interact with the ————— forms of the Na+ channel, blocking Na+ conductance. They are not effective outside the axon.

Answer 11

open and inactivated

Question 12

Because local anesthetics bind to the open form of the sodium channel, they produce a more

Answer 12

rapid nerve block on axons with a more rapid firing rate.

Question 13

1. Functions served by ——— are more readily disrupted by local anesthetics than the —————

Answer 13

B and C fibers

motor functions served by (larger) A fibers*

Question 14

2. Sensory neurons are ———–in size and sensitivity

Answer 14

heterogeneous

Question 15

The faster a fiber is blocked, the ——- it takes to recover

Answer 15

longer - first on first off.

Question 16

Block more

Answer 16

rapid with rapidly firing nerves

Question 17

Inflamed tissue is more difficult to anesthetize.

Products released by cells in inflamed tissue lower

Answer 17

pH, making it more difficult to get sufficient levels of anesthetic inside the axon.

Question 18

If epinephrine is included, the pH is frequently lowered to ——– to stabilize the epinephrine.

Answer 18

4 or 5

Question 19

The buffering capacity at the injection site should ————-

Answer 19

neutralize this lower pH from stabilizing epinephrine

Question 20

Risk of adding bicarbonate before injection?

Answer 20

precipitating anesthetic.

Question 21

Direct effects on the heart local anesthetic.

Answer 21

Block cardiac Na+ channels Block cardiac Ca++ channels (much higher concentrations)

Question 22

Effects on the autonomic nervous system: (inhibition of sympathetic responses)

Answer 22

Depress contractility, produce hypotension

Question 23

-zosin

Answer 23

a1-adrenergic receptor blocker

Question 24

-olol

Answer 24

b-adrenergic receptor blocker

Question 25

-alol, -ilol

Answer 25

b-adrenergic receptor blocker, with a1 activity