QUESTIONS AND ANSWERS 100%
CORRECT
Ester Local Anesthetics (5) - ANSWER-- Cocaine
- Procaine
- Chloroprocaine
- Tetracaine
- Benzocaine
(only 1 "i" in the name)
Amide Local Anesthetics (6) - ANSWER-- Lidocaine
- Prilocaine
- Ropivicaine
- Bupivacaine
- Articaine
- Mepivicaine
(2 "i's" in the name)
Miscellaneous drugs associated with Local Anesthetics - ANSWER-- EMLA Cream
- Hyaluronidase
- Oraverse
Three required chemical components of the local anesthetic molecule - ANSWER-1.
Lipophilic portion (Benzene ring)
2. Hydrophilic portion (Quarternary amine)
3. Separated by an Intermediate Chain (either an Ester or Amide chain)
Amide Intermediate bond characteristics - ANSWER-NH (positively charged) and
Carbonyl oxygen (negatively charged) = attracted to each other → difficult to separate =
difficult to metabolize
Ester Intermediate bond characteristics - ANSWER-Oxygen (negatively charged) and
Carbonyl oxygen (negatively charged) = repel each other → open bond = easy to
metabolize
All local anesthetics take on these 2 forms to be non-ionized or ionized depending on
the pH - ANSWER-1. Quarternary amine (charged nitrogen group) → water soluble
2. Tertiary Amine (non-charged nitrogen group) → lipid soluble
Ester metabolism
1. Metabolized by
, 2. Metabolized in
3. Fast or slow metabolism
4. Duration of action
5. Longest acting Ester - ANSWER-1. (Location specific) Esterases
2. Everywhere
3. Fast
4. Short
5. Tetracaine
Amide metabolism
1. Metabolized by
2. Metabolized in
3. Fast or slow metabolism
4. Duration of action
5. Risk with Amide local anesthetic metabolism - ANSWER-1. Liver enzymes (CYP1A2
and CYP3A4)
2. Liver
3. Slow
4. Long: highly protein bound and liver metabolism
5. Rapid absorption can lead to significant blood level → toxicity
Which local anesthetic type has a higher allergy probability? - ANSWER-Esters
1. If a patient is allergic to an ester local anesthetic, are they allergic to all other ester
anesthetics?
2. Are they allergic to the amides? - ANSWER-1. Yes
2. No
1. If a patient is allergic to an amide local anesthetic, are they allergic to all other amide
anesthetics?
2. Are they allergic to the esters? - ANSWER-1. No
2. No
Local anesthetic mechanism of action (except Benzocaine) - ANSWER-1. Inject local
anesthetic into tissue
2. Non-ionized form crosses the membrane
3. In new pH of the cytoplasm, some of the non-ionized LA becomes ionized
4. Ionized LA enters the sodium channel and blocks sodium influx
Benzocaine mechanism of action - ANSWER-1. Inject local anesthetic into tissue
2. Ionized form of the drug enters the sodium channel of the neuron and blocks sodium
influx
Injected Local Anesthetic goes to these 3 places - ANSWER-1. Nerve blockade (non-
ionized)
2. Blood stream uptake & removal (absorption → drug wears off)