DAANCE Anesthetic Pharmacology 5 — Questions and Answers
Question 1: Which of the following drugs is classified as a non-opioid analgesic that works centrally and is commonly used as premedication for dental sedation?
- Midazolam
- Hydroxyzine
- Ketorolac
- Acetaminophen (Correct answer)
Correct answer: Acetaminophen
Acetaminophen is a centrally acting non-opioid analgesic used for premedication and multimodal analgesia in dental sedation protocols.
Question 2: The primary mechanism by which local anesthetics block nerve conduction is:
- Blocking potassium channels during repolarization
- Binding to voltage-gated sodium channels in the inactivated state (Correct answer)
- Stimulating GABA receptors to hyperpolarize the membrane
- Inhibiting acetylcholine release at the synapse
Correct answer: Binding to voltage-gated sodium channels in the inactivated state
Local anesthetics bind to voltage-gated sodium channels in their inactivated state, preventing sodium influx and halting action potential propagation.
Question 3: A patient receiving IV propofol sedation develops apnea. Which of the following best explains this adverse effect?
- Propofol stimulates opioid receptors in the brainstem
- Propofol potentiates GABA-A receptors, depressing respiratory drive (Correct answer)
- Propofol blocks NMDA receptors causing airway muscle paralysis
- Propofol depletes acetylcholine at the neuromuscular junction
Correct answer: Propofol potentiates GABA-A receptors, depressing respiratory drive
Propofol enhances inhibitory GABA-A receptor activity, which at higher doses suppresses the brainstem respiratory center.
Question 4: Which local anesthetic is unique in that it is an ester with an amide linkage within the same molecule and is delivered in cartridges with epinephrine for dental use?
- Mepivacaine
- Articaine (Correct answer)
- Lidocaine
- Prilocaine
Correct answer: Articaine
Articaine is a hybrid molecule containing both an amide and an ester group, allowing it to be metabolized in plasma as well as in the liver.
Question 5: Methemoglobinemia is a known toxic complication associated with which local anesthetic?
- Bupivacaine
- Lidocaine
- Prilocaine (Correct answer)
- Mepivacaine
Correct answer: Prilocaine
Prilocaine's metabolite ortho-toluidine oxidizes hemoglobin to methemoglobin, reducing oxygen-carrying capacity.
Question 6: In pharmacokinetics, the 'volume of distribution' (Vd) of a sedation drug describes:
- The rate at which the drug is eliminated from the plasma
- The maximum concentration the drug reaches in the bloodstream
- How widely the drug distributes throughout the body relative to plasma concentration (Correct answer)
- The fraction of the drug that reaches systemic circulation after administration
Correct answer: How widely the drug distributes throughout the body relative to plasma concentration
Volume of distribution reflects the extent to which a drug distributes into body tissues compared to remaining in plasma — a high Vd means extensive tissue uptake.
Question 7: Which of the following best describes tachyphylaxis in the context of sedation pharmacology?
- An allergic reaction that worsens with each subsequent dose
- A rapid decrease in response to a drug after repeated administration (Correct answer)
- An increase in drug potency over time due to receptor upregulation
- A delayed onset of drug action following the first dose
Correct answer: A rapid decrease in response to a drug after repeated administration
Tachyphylaxis is acute tolerance characterized by rapidly diminishing drug effect with repeated short-interval dosing.
DAANCE Anesthetic Pharmacology 5
Which of the following drugs is classified as a non-opioid analgesic that works centrally and is commonly used as premedication for dental sedation?