NBDE Pharmacology and Pain Control 4 — Questions and Answers
Question 1: A patient taking MAO inhibitors presents for dental treatment requiring pain control. Which drug combination poses the greatest risk?
- Ibuprofen + lidocaine
- Meperidine + phenelzine (Correct answer)
- Acetaminophen + bupivacaine
- Codeine + diazepam
Correct answer: Meperidine + phenelzine
Meperidine combined with MAO inhibitors can cause a life-threatening serotonin syndrome, manifesting as hyperthermia, seizures, and cardiovascular collapse.
Question 2: Which reversal agent is used to treat severe benzodiazepine sedation during dental procedures?
- Naloxone
- Flumazenil (Correct answer)
- Physostigmine
- Atropine
Correct answer: Flumazenil
Flumazenil is a competitive benzodiazepine receptor antagonist that rapidly reverses CNS depression caused by benzodiazepine overdose.
Question 3: Articaine differs from other amide local anesthetics in that it contains:
- An ester linkage in addition to an amide bond
- A thiophene ring instead of a benzene ring (Correct answer)
- A quaternary ammonium group for improved diffusion
- A fluorine atom for enhanced potency
Correct answer: A thiophene ring instead of a benzene ring
Articaine uniquely contains a thiophene ring (instead of a benzene ring) and an additional ester group, allowing rapid plasma hydrolysis and a shorter systemic half-life.
Question 4: In dentistry, the vasoconstrictive concentration of epinephrine most commonly used is:
- 1:10,000
- 1:50,000
- 1:100,000 (Correct answer)
- 1:200,000
Correct answer: 1:100,000
A 1:100,000 epinephrine concentration (10 mcg/mL) provides adequate vasoconstriction to prolong anesthesia and limit bleeding without significant cardiovascular risk in most patients.
Question 5: Which analgesic mechanism best describes the action of NSAIDs?
- Blocking mu-opioid receptors in the spinal cord
- Inhibiting cyclooxygenase enzymes and prostaglandin synthesis (Correct answer)
- Antagonizing substance P at NK1 receptors
- Enhancing descending serotonergic pain inhibition
Correct answer: Inhibiting cyclooxygenase enzymes and prostaglandin synthesis
NSAIDs inhibit cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis and thereby decreasing peripheral sensitization and inflammation-mediated pain.
Question 6: Prolonged use of which local anesthetic has been associated with causing permanent paresthesia, particularly with inferior alveolar nerve blocks?
- Lidocaine
- Mepivacaine
- Articaine (Correct answer)
- Prilocaine
Correct answer: Articaine
Articaine, especially at 4% concentration, has been epidemiologically associated with a higher incidence of persistent paresthesia following inferior alveolar and lingual nerve blocks.
Question 7: A patient with sulfonamide allergy asks about pain control options. Which drug should be avoided?
- Ibuprofen
- Celecoxib (Correct answer)
- Naproxen
- Acetaminophen
Correct answer: Celecoxib
Celecoxib contains a sulfonamide moiety and may cross-react in patients with sulfonamide allergies, potentially causing hypersensitivity reactions.
NBDE Pharmacology and Pain Control 4
A patient taking MAO inhibitors presents for dental treatment requiring pain control.
Which drug combination poses the greatest risk?