Preparing for the RDN (Registered Dietitian Nutritionist) exam? Pharmacology is one of the areas our deck drills hardest: 40 of its 1070 flashcards focus on pharmacology, covering topics like Dyrenium. Try the sample questions below — every card is a real question-and-answer pair from the full deck.
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A patient on Warfarin begins a green smoothie challenge, consuming 3 cups of spinach daily. Their INR drops from 2.5 to 1.4. What is the primary pathophysiological reason and RDN recommendation?
Show answer →Warfarin inhibits Vitamin K epoxide reductase, preventing the recycling of Vitamin K. High Vitamin K intake provides more substrate for clotting factor synthesis (II, VII, IX, X), antagonizing the drug. RDN Recommendation: Do NOT stop the spinach; instead, maintain a consistent daily intake. The medical team will adjust the Warfarin dose to match this new stable intake. CDR Exam Tip: Avoidance is an incorrect distractor; consistency is the gold standard for Warfarin counseling.
A patient has a known genetic polymorphism in the VKORC1 gene. How does this affect the RD's approach to their nutritional counseling regarding Vitamin K?
Show answer →The VKORC1 (Vitamin K Epoxide Reductase Complex 1) gene encodes the enzyme that Warfarin targets. Patients with certain polymorphisms (e.g., the A haplotype) are highly sensitive to Warfarin and require lower doses. These patients are at a much higher risk of INR instability. For the RD, this necessitates even stricter emphasis on day-to-day consistency of Vitamin K intake, as even small deviations can cause significant INR swings compared to the general population.
While evidence is evolving in 2026, statin-induced myopathy is often linked to the depletion of which endogenous antioxidant, and what is the proposed mechanism?
Show answer →Coenzyme Q10 (Ubiquinone). Statins inhibit HMG-CoA reductase, the rate-limiting step in the mevalonate pathway. This pathway produces both cholesterol and farnesyl pyrophosphate, a precursor to CoQ10. Depletion may impair mitochondrial oxidative phosphorylation in muscle cells. CDR Focus: While supplementation is widely debated, RDs must recognize the biochemical pathway interruption.
A patient is prescribed Triamterene (Dyrenium) for edema. What specific nutrient-drug interaction should the RDN monitor over long-term therapy?
Show answer →Folic Acid. Triamterene is a weak folic acid antagonist as it inhibits dihydrofolate reductase. Long-term use can lead to megaloblastic anemia. CDR Tip: Differentiate Triamterene from other K-sparing diuretics like Spironolactone, which do not have this specific anti-folate mechanism. This is a common distractor on the exam.
A patient taking Acarbose experiences a hypoglycemic episode (BG 62 mg/dL). Why must the RDN instruct the patient to avoid using table sugar or soda to treat this event?
Show answer →Acarbose (an alpha-glucosidase inhibitor) inhibits the enzyme that breaks down disaccharides (sucrose/table sugar) into monosaccharides. Treatment with sucrose will be delayed in absorption and fail to raise BG quickly. Rationale: Only pure glucose (dextrose) or lactose (milk) should be used. Exam Tip: This is a classic mechanism-to-practice question on the CDR exam.
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Try 30 free RDN cards firstThe full RDN deck contains 1070 flashcards, and 40 of them focus on pharmacology. This page shows 5 free samples.
Our RDN deck dedicates 40 of 1070 cards (4%) to pharmacology — always cross-check the official CDR exam outline for the current blueprint weighting.
Yes — the samples on this page are free, and the RDN preview page has 30 more free cards. Full access to all 1070 cards is a one-time $7.
Assessment
70 cards
Basics
110 cards
Management
300 cards
Pathology
270 cards
Physiology
140 cards
Procedures
110 cards
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