Local Analgesia

Question 0

How do NSAIDs affect the kidney?

Answer 0

Prostaglandins promote blood flow there

NSAIDs inhibit this so vasoconstriction

Question 1

How does aspirin cause tinnitus?

Answer 1

NMDA receptors

Question 2

What is Reye’s syndrome?

Answer 2

Swelling of the lover and brain
Diarrhea and rapid breathing
Vomiting 
Confusion
Seizures

Question 3

Where do local anesthetics act?

Answer 3

Prevent transmission of pain
Numbness
Loss of sensation

Question 4

Where do local anesthetics act?

Answer 4

Block sodium channels

Question 5

What are the three structural components of local anesthetics?

Answer 5

Hydrophobic - potency, duration of action, toxicity

Intermediate linker component - two class, ester and amide.
Esters are rapidly broken down and high allergy rate
Amides are more stable

Hydrophilic component - an amine, determines pka, impacts onset of action

Question 6

What pk are local anesthetics?

Answer 6

Weak bases

Pk 8-9

Question 7

What form of the drug is important?

Answer 7

Both the ionized and unionized form

Ionized has the proton

Question 8

What form of the drug can go through the membrane?

Answer 8

The unionized form

Question 9

What form of the drug blocks sodium channels?

Answer 9

The ionized form

Question 10

What pk acts faster?

Answer 10

Lower

Question 11

What states do local anesthetics act on?

Answer 11

The open or inactive state

Question 12

What do local anesthetics preferentially block?

Answer 12

Smaller diameter fibers

Myelinated

Question 13

What other effects do local anesthetics have?

Answer 13

Vasodilation - risks clearance and diffuse effect

Question 14

How do you decrease the risk of toxicity for local anesthetics?

Answer 14

Add a vasoconstriction

Question 15

What is the metabolite of ester local anesthetics that produce an allergic reaction?

Answer 15

PABA para-amino benzoic acid

Question 16

What are common vasocontrictors that are used with local anesthetics?

Answer 16

Epinephrine

Question 17

What do you have to worry about using local anesthetics?

Answer 17

Inflammation and pus because they lower the pH to 6.5 and 5.5 respectively

Question 18

Which local anesthetic is fastly metabolized in the plasma and by what?

Answer 18

Ester form

By pseudo choline esterases

Question 19

What is EMLA?

Answer 19

Enteric mixture of Local anesthetics

A mixture of two drugs that together has a lower mp

Question 20

What route of anesthetic is most common?

Answer 20

Infiltration

Subcutaneous or submucosal injection

Question 21

What is a nerve block?

Answer 21

Major or minor block of a peripheral nerve

Question 22

What is a IV region block?

Answer 22

In the blood stream with a tourniquet to localize the drug placing

Question 23

When do you use an epidural anesthesia?

Answer 23

Long procedures

Labor

Question 24

When do you use a spinal anesthetic?

Answer 24

Some time

Question 25

What is procaine?

Answer 25

An ester type
Short acting
Not useful as a topical drug

Question 26

What is lidocaine?

Answer 26

Amide type
Metabolized by liver
Death if systemic
Work hoarse.

Question 27

What is mepivacaine?

Answer 27

Amide like lidocaine
Long acting
Not topically

Question 28

What is bupivacaine?

Answer 28

Amide
Longest acting
Most common for prolonged surgery

Question 29

What is ropivacaine?

Answer 29

Amide type
Long
Less cv and CNS toxicity that bupivacaine

Question 30

What is tetracaine?

Answer 30

Ester type

Used in the eye, nose, throat and spinal

Question 31

What is cocaine?

Answer 31

Ester type
Good penetration
Upper respiratory, mucosal membrane
Abuse potential