Pharmacology - Chapter 26 - Local Anesthetics

Question 1

Local anesthetics - drugs that suppress pain by…

Answer 1

blocked impulse conduction.

Question 2

What are a few advantages of local anesthetics?

Answer 2

Pain is suppressed without causing generalized depression of the nervous system. They are also safer than general anesthesia.

Question 3

Local anesthetics - MOA

Answer 3

Stop axonal conduction by blocking sodium channels. Blocks all neuronal function, both sensory and motor.

Question 4

Local Anesthetics - have lots of selectivity. T/F?

Answer 4

False! They are not at all selective. They will block any and everything it can.

Question 5

Axonal conduction in non-myelinated neurons are blocked more easily than myelinated neurons. T/F?

Answer 5

True!

Question 6

Time course of action - Local Anesthetics - usually begins…..

Answer 6

usually begins promptly and persists no longer than needed.

Question 7

Local anesthetics are usually used in conjunction with a ???

Answer 7

Vasonconstrictor.

Question 8

Why are local anesthetics used with vasoconstrictors?

Answer 8

They delay absorption, reduce toxicity, prolong effects, etc.

Question 9

What are the two classifications of local anesthetics?

Answer 9

Esters and Amides.

Question 10

Esters are…

Answer 10

procaines.

Question 11

Amides are…

Answer 11

lidocaines.

Question 12

Esters - metabolized by ___ in the ___.

Answer 12

Esterases in the blood.

Question 13

Amides - metabolized by ___ in the ___.

Answer 13

Enzymes in the liver.

Question 14

What are some adverse effects of local anesthetics?

Answer 14

CNS - causes excitation, followed by depression. Allergic reactions, bradycardia, etc.

Question 15

Procaine is very effective topically. T/F?

Answer 15

FALSE. It is not at all effective topically.

Question 16

Procaine must be administered ___

Answer 16

by injection.

Question 17

Cocaine is a ___ type.

Answer 17

Ester.

Question 18

Cocaine causes intense constriction. T/F?

Answer 18

True!

Question 19

Infiltration anesthesia - basic info.

Answer 19

Inject directly into immediate area of surgery. Lidocaine, bupivacaine.

Question 20

Nerve block anesthesia - basic info.

Answer 20

Inject into nerves that supply surgical field but which are distant from field. Lidocaine, mepivacaine (for short procedure) or bupivacaine (for longer procedure.)

Question 21

Intravenous regional anesthesia - basic info.

Answer 21

Anesthetize extremities (not entire arm or leg) by 1st removal of blood and then injection into vein. Does not want anesthetic to go into general circulation. Lidocaine without epinephrine.

Question 22

Epidural anesthesia - basic info.

Answer 22

Inject local anesthetic into the epidural space. Blocks conduction in nerve roots and in the spinal cord. Lidocaine/bupivacaine.