Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
Describe the chemistry of local anesthetics
|
Lipophilic group (Aromatic ring) --Intermediate chain (Ester or amide) -- Ionizable group (Tertiary amine)
|
|
|
The two main subclasses of local anesthetics are:
|
Amides
Esters |
|
|
What is the MOA of local anesthetics?
|
Na channel blockers, reduce sodium influx. This prevents depolarization and blocks conduction of the action potential.
|
|
|
Name two long duration amides
|
Bupivacaine
Ropivacaine |
|
|
Medium duration amide
|
Lidocaine
|
|
|
List 5 drugs that containe esters as intermediate chain in local anesthtics:
|
Benzocaine
Cocaine Procaine Tetracaine |
|
|
A long duration ester containing local anesthetic:
|
Tetracaine
|
|
|
A short duration ester containing local anesthetic:
|
procaine
|
|
|
Medium duration ester containing local anesthetic:
|
Cocaine
|
|
|
Surface active ester containing local anesthetic:
|
Benzocaine
Cocaine |
|
|
True or False:
All local anesthetics are vasodilators |
False,
All except cocaine |
|
|
Why are short acting local anesthetics given with vasoconstrictors?
|
Reducing blood flow to injection point allows the drug to sit there longer and increases the duration of action.
|
|
|
Which local anesthetics can be used as topical anesthesia?
|
Benzocaine and cocaine
|
|
|
How are esters metabolized?
|
Pseudocholinesterase
|
|
|
How are amides metabolized?
|
Hepatic microsomal enzymes. Therefore liver problems may increase their elimination half-life.
|
|
|
Which nn. fibers are blocked more easily by local anesthetics? Small or large nerve fibers
|
Small diameter
|
|
|
Which nn. fibers are blocked more easily by local anesthetics? myelinated or unmyelinated nerve fibers
|
myelinated - electrical signals travel faster in these nerves.
|
|
|
Which nn. fibers are blocked more easily by local anesthetics? peripheral or core nerve fibers
|
peripheral - Exposed sooner to a higher concentration of the anesthetic.
|
|
|
List the factors that determine the susceptibility of nn fibers to blockade
|
Size - small/ large diameter
Myelin Peripheral/core |
|
|
List the major toxic effects of local anesthetics:
|
CNS - lightheaded, nystagmus, resp. & cardiovascular collapse.
Cardiovascular - all local anesthetics are vasodilators exc. cocaine. Allergic Rxns: With ester type allergic reactions. |
|
|
Prototype drug for Ester subclass
|
Procaine
Cocaine: Major variant |
|
|
Prototype drug for amide subclass
|
Lidocaine
|
|
|
How are convulsions due to local anesthetic toxicity treated?
|
Diazepam or barbiturates
|
|
|
What are the cardiovascular symptoms seen with cocaine toxicity?
|
Hypertension, cerebral hemorrhage, cardiac arrhythmias and myocardial infarction.
|
