DAANCE Pharmacology 4 — Questions and Answers
Question 1: Which opioid analgesic is most commonly used as a component of balanced anesthesia in dental sedation due to its rapid onset and short duration?
- Morphine
- Fentanyl (Correct answer)
- Meperidine
- Hydromorphone
Correct answer: Fentanyl
Fentanyl is preferred for dental sedation because of its rapid onset (1-2 minutes) and relatively short duration (30-60 minutes), making it ideal for titration.
Question 2: A patient receiving nitrous oxide/oxygen sedation suddenly develops hypoxia. The MOST appropriate immediate action is to:
- Increase the nitrous oxide concentration
- Administer 100% oxygen and discontinue nitrous oxide (Correct answer)
- Administer flumazenil IV
- Reduce the oxygen flow rate
Correct answer: Administer 100% oxygen and discontinue nitrous oxide
When hypoxia occurs during N2O sedation, 100% oxygen must be administered immediately and nitrous oxide discontinued to prevent diffusion hypoxia and restore adequate oxygenation.
Question 3: Midazolam produces anterograde amnesia primarily by acting on which receptor type?
- Opioid mu receptors
- GABA-A receptors (Correct answer)
- NMDA receptors
- Alpha-2 adrenergic receptors
Correct answer: GABA-A receptors
Midazolam enhances GABA-A receptor chloride ion conductance, producing CNS depression, anxiolysis, and anterograde amnesia.
Question 4: Which drug is classified as an alpha-2 adrenergic agonist and is sometimes used as an adjunct in sedation for its anxiolytic and analgesic-sparing properties?
- Ketamine
- Dexmedetomidine (Correct answer)
- Propofol
- Etomidate
Correct answer: Dexmedetomidine
Dexmedetomidine is a highly selective alpha-2 adrenergic agonist that provides sedation, anxiolysis, and analgesia with minimal respiratory depression.
Question 5: The maximum recommended dose of lidocaine WITH epinephrine for a healthy adult dental patient is:
- 3.2 mg/kg up to 200 mg
- 4.4 mg/kg up to 300 mg
- 7 mg/kg up to 500 mg (Correct answer)
- 10 mg/kg up to 700 mg
Correct answer: 7 mg/kg up to 500 mg
Lidocaine with epinephrine has a maximum dose of 7 mg/kg, not to exceed 500 mg in a healthy adult, because epinephrine reduces systemic absorption.
Question 6: Which benzodiazepine has the LONGEST elimination half-life and carries the greatest risk of cumulative sedation with repeated dosing?
- Midazolam
- Lorazepam
- Diazepam (Correct answer)
- Triazolam
Correct answer: Diazepam
Diazepam has an elimination half-life of 20-100 hours (plus active metabolites), making accumulation a significant concern with repeated doses.
Question 7: Methemoglobinemia is a known toxic risk associated with excessive doses of which local anesthetic?
- Lidocaine
- Bupivacaine
- Prilocaine (Correct answer)
- Mepivacaine
Correct answer: Prilocaine
Prilocaine is metabolized to o-toluidine, which oxidizes hemoglobin to methemoglobin, impairing oxygen-carrying capacity at higher doses.
DAANCE Pharmacology 4
Which opioid analgesic is most commonly used as a component of balanced anesthesia in dental sedation due to its rapid onset and short duration?