NBDHE NBDHE Pharmacology in Dental Hygiene 3 — Questions and Answers
Question 1: A patient is prescribed metronidazole for a periodontal abscess. Which substance must be strictly avoided during and 48 hours after therapy?
- Dairy products
- Alcohol (Correct answer)
- Grapefruit juice
- Antacids
Correct answer: Alcohol
Metronidazole inhibits aldehyde dehydrogenase; alcohol consumption causes a disulfiram-like reaction with nausea, vomiting, and flushing.
Question 2: Which local anesthetic has the longest duration of action and is most appropriate for post-operative pain management after oral surgery?
- Lidocaine 2%
- Mepivacaine 3%
- Articaine 4%
- Bupivacaine 0.5% (Correct answer)
Correct answer: Bupivacaine 0.5%
Bupivacaine 0.5% provides the longest duration of action (4–9 hours pulpal, 12+ hours soft tissue) among dental local anesthetics.
Question 3: A patient with G6PD deficiency is at increased risk for hemolytic anemia when taking which drug commonly used in dentistry?
- Amoxicillin
- Prilocaine (Correct answer)
- Lidocaine
- Bupivacaine
Correct answer: Prilocaine
Prilocaine's metabolite o-toluidine can cause methemoglobinemia and trigger hemolysis in G6PD-deficient patients.
Question 4: Tetracycline-induced tooth staining occurs when the drug is administered during which period?
- First trimester of pregnancy only
- During tooth mineralization (fetal through age 8) (Correct answer)
- After permanent tooth eruption
- During root development only
Correct answer: During tooth mineralization (fetal through age 8)
Tetracycline binds to calcium in mineralizing tooth structure during the period of active tooth development, from the second trimester of pregnancy through approximately age 8.
Question 5: Which mechanism best explains why erythromycin increases the plasma level of cyclosporine in transplant patients receiving dental antibiotic therapy?
- Erythromycin increases GI absorption of cyclosporine
- Erythromycin inhibits CYP3A4, reducing cyclosporine metabolism (Correct answer)
- Erythromycin displaces cyclosporine from plasma proteins
- Erythromycin reduces renal clearance of cyclosporine
Correct answer: Erythromycin inhibits CYP3A4, reducing cyclosporine metabolism
Erythromycin is a potent CYP3A4 inhibitor, which reduces first-pass and hepatic metabolism of cyclosporine, elevating its plasma concentration.
Question 6: A patient taking phenytoin for epilepsy presents with overgrown gingival tissue. This drug-induced gingival overgrowth is worsened by which factor?
- High phenytoin plasma concentration alone
- Poor oral hygiene and plaque accumulation (Correct answer)
- Duration of therapy less than 6 months
- Female sex and hormonal status
Correct answer: Poor oral hygiene and plaque accumulation
Poor oral hygiene and plaque-induced inflammation are the primary local factors that exacerbate phenytoin-induced gingival overgrowth.
Question 7: Which opioid analgesic is considered safest for a patient with severe liver disease requiring dental pain management?
- Codeine
- Hydrocodone
- Tramadol (Correct answer)
- Acetaminophen with opioid combination
Correct answer: Tramadol
While all opioids require caution in hepatic disease, tramadol at reduced doses is generally better tolerated than pro-drug opioids requiring hepatic activation like codeine.
NBDHE NBDHE Pharmacology in Dental Hygiene 3
A patient is prescribed metronidazole for a periodontal abscess.
Which substance must be strictly avoided during and 48 hours after therapy?