DAANCE Anesthetic Pharmacology 4 — Questions and Answers
Question 1: Which opioid used in dental sedation has the SHORTEST duration of action and is most suitable for brief procedures?
- Morphine
- Fentanyl (Correct answer)
- Meperidine
- Hydromorphone
Correct answer: Fentanyl
Fentanyl has a very short duration of action (30–60 minutes) and rapid onset, making it ideal for short dental procedures.
Question 2: The reversal agent for benzodiazepine-induced sedation is:
- Naloxone
- Physostigmine
- Flumazenil (Correct answer)
- Neostigmine
Correct answer: Flumazenil
Flumazenil is a competitive benzodiazepine receptor antagonist that rapidly reverses benzodiazepine sedation.
Question 3: Which local anesthetic has the LONGEST duration of action and is classified as an amide?
- Procaine
- Prilocaine
- Bupivacaine (Correct answer)
- Articaine
Correct answer: Bupivacaine
Bupivacaine is a long-acting amide local anesthetic with a duration of 4–8 hours, used when prolonged anesthesia is needed.
Question 4: Ketamine produces a dissociative anesthetic state primarily by antagonizing which receptor?
- GABA-A receptor
- Opioid mu receptor
- NMDA receptor (Correct answer)
- Alpha-2 adrenergic receptor
Correct answer: NMDA receptor
Ketamine blocks NMDA (N-methyl-D-aspartate) glutamate receptors, producing dissociative anesthesia with analgesia and amnesia.
Question 5: A patient receiving nitrous oxide sedation suddenly becomes agitated and combative. The MOST appropriate initial action is to:
- Increase the nitrous oxide concentration
- Administer IV midazolam immediately
- Reduce or discontinue nitrous oxide and increase oxygen (Correct answer)
- Administer flumazenil
Correct answer: Reduce or discontinue nitrous oxide and increase oxygen
Agitation during nitrous oxide sedation may indicate an excitatory reaction; reducing N2O and increasing O2 is the safest first step.
Question 6: Which property of a local anesthetic is most directly related to its POTENCY?
- pKa value
- Protein binding percentage
- Lipid solubility (Correct answer)
- Water solubility
Correct answer: Lipid solubility
Lipid solubility determines a local anesthetic's ability to penetrate nerve membranes and directly correlates with potency.
Question 7: The addition of a vasoconstrictor such as epinephrine to a local anesthetic solution primarily serves to:
- Increase systemic absorption and speed onset
- Decrease the pH of the solution to improve patient comfort
- Prolong duration of action and reduce systemic toxicity (Correct answer)
- Antagonize the local anesthetic at the receptor site
Correct answer: Prolong duration of action and reduce systemic toxicity
Vasoconstrictors reduce local blood flow, slowing absorption, prolonging anesthetic effect, and lowering peak plasma concentration.
DAANCE Anesthetic Pharmacology 4
Which opioid used in dental sedation has the SHORTEST duration of action and is most suitable for brief procedures?