DPM Pharmacology & Therapeutics 2 — Questions and Answers
Question 1: A patient with gout is started on allopurinol. Which mechanism best describes how this drug reduces uric acid levels?
- Inhibits xanthine oxidase (Correct answer)
- Promotes renal uric acid excretion
- Blocks uric acid synthesis via COX-2
- Increases urinary pH to dissolve crystals
Correct answer: Inhibits xanthine oxidase
Allopurinol is a xanthine oxidase inhibitor that reduces conversion of hypoxanthine and xanthine to uric acid.
Question 2: Which topical antifungal is classified as an allylamine and is first-line for tinea pedis (athlete's foot)?
- Clotrimazole
- Terbinafine (Correct answer)
- Nystatin
- Ciclopirox
Correct answer: Terbinafine
Terbinafine, an allylamine, inhibits squalene epoxidase and is highly effective for dermatophyte infections like tinea pedis.
Question 3: A diabetic patient requires local anesthesia for a minor foot procedure. Which local anesthetic has the LONGEST duration of action?
- Lidocaine
- Mepivacaine
- Bupivacaine (Correct answer)
- Prilocaine
Correct answer: Bupivacaine
Bupivacaine has a duration of action of 4–8 hours, making it the longest-acting amide local anesthetic commonly used in podiatric procedures.
Question 4: Probenecid is used as adjunctive therapy in gout management. What is its primary mechanism?
- Inhibits uric acid synthesis
- Blocks renal tubular reabsorption of uric acid (uricosuric) (Correct answer)
- Increases urinary excretion of calcium
- Inhibits prostaglandin synthesis
Correct answer: Blocks renal tubular reabsorption of uric acid (uricosuric)
Probenecid is a uricosuric agent that inhibits URAT1 transporter in the proximal tubule, blocking reabsorption and increasing urinary uric acid excretion.
Question 5: A patient on warfarin for DVT develops a foot infection requiring antibiotics. Which antibiotic class is MOST likely to significantly increase warfarin's INR?
- Aminoglycosides
- Fluoroquinolones (Correct answer)
- Tetracyclines
- Macrolides
Correct answer: Fluoroquinolones
Fluoroquinolones inhibit CYP1A2 and reduce vitamin K-producing gut flora, significantly potentiating warfarin's anticoagulant effect.
Question 6: Which opioid analgesic is considered SAFEST in patients with severe renal impairment due to lack of active metabolite accumulation?
- Morphine
- Codeine
- Hydromorphone
- Fentanyl (Correct answer)
Correct answer: Fentanyl
Fentanyl is hepatically metabolized to inactive metabolites and does not accumulate dangerously in renal impairment, unlike morphine or codeine.
Question 7: A patient develops contact dermatitis from a topical antibiotic used post-operatively on a foot wound. Which agent is MOST commonly implicated?
- Mupirocin
- Bacitracin (Correct answer)
- Silver sulfadiazine
- Gentamicin cream
Correct answer: Bacitracin
Bacitracin is one of the most common causes of allergic contact dermatitis among topical antibiotics due to its high sensitization rate.
DPM Pharmacology & Therapeutics 2
A patient with gout is started on allopurinol.
Which mechanism best describes how this drug reduces uric acid levels?