Dosing medications in patients with renal dysfunction is a critical, everyday responsibility for pharmacists that directly impacts patient safety. This “transcending concept,” a cornerstone of the Patient Care 4 and Principles of Drug Therapy Individualization curricula, requires the application of pharmacokinetic principles to prevent drug accumulation and toxicity. This quiz will test your knowledge on the methods for dose adjustment, considerations for specific high-risk drugs, and the unique challenges of dosing in patients with impaired kidney function and those on dialysis.
1. What is the primary reason for adjusting the dose of a medication in a patient with renal dysfunction?
- a. To increase the drug’s efficacy.
- b. To prevent the accumulation of the drug or its active/toxic metabolites.
- c. To decrease the cost of therapy.
- d. To make the dosing schedule more convenient.
Answer: b. To prevent the accumulation of the drug or its active/toxic metabolites.
2. A drug is 95% eliminated unchanged by the kidneys and has a narrow therapeutic index. This drug will likely:
- a. Not require any dose adjustment in renal impairment.
- b. Require significant dose adjustment in renal impairment.
- c. Be safer in patients with renal impairment.
- d. Be dosed based on liver function.
Answer: b. Require significant dose adjustment in renal impairment.
3. The two primary methods for adjusting drug therapy in renal dysfunction are reducing the dose or:
- a. Increasing the dose.
- b. Extending the dosing interval.
- c. Shortening the dosing interval.
- d. Switching to an IV formulation.
Answer: b. Extending the dosing interval.
4. Which characteristic makes a drug more likely to be removed by hemodialysis?
- a. High molecular weight and high protein binding.
- b. Large volume of distribution.
- c. Low molecular weight and low protein binding.
- d. High lipophilicity.
Answer: c. Low molecular weight and low protein binding.
5. For a drug that is removed by hemodialysis, when should a scheduled dose be administered?
- a. During the dialysis session.
- b. Immediately before the dialysis session.
- c. After the dialysis session.
- d. The timing does not matter.
Answer: c. After the dialysis session.
6. The “Dosing in Renal Dysfunction” lecture is a specific “Transcending Concept” in which course?
- a. PHA5784C Patient Care 4
- b. PHA5104 Sterile Compounding
- c. PHA5703 Pharmacy Law and Ethics
- d. PHA5878C Patient Care 3
Answer: a. PHA5784C Patient Care 4
7. For time-dependent antibiotics like most beta-lactams, which dose adjustment strategy may be preferred to maintain concentrations above the MIC?
- a. Decreasing the dose and shortening the interval.
- b. Maintaining a similar dose and extending the interval.
- c. Giving a very large dose once a week.
- d. Dose adjustment is not needed for beta-lactams.
Answer: b. Maintaining a similar dose and extending the interval.
8. Metformin is contraindicated in patients with severe renal dysfunction (e.g., eGFR < 30 mL/min/1.73m²) due to an increased risk of:
- a. Hypoglycemia
- b. Hepatotoxicity
- c. Lactic acidosis
- d. Severe constipation
Answer: c. Lactic acidosis
9. Enoxaparin (a low-molecular-weight heparin) requires dose adjustment or avoidance in severe renal impairment because:
- a. It is not effective in these patients.
- b. It accumulates and increases the risk of bleeding.
- c. It is highly dialyzable.
- d. It causes hyperkalemia.
Answer: b. It accumulates and increases the risk of bleeding.
10. Which of the following direct oral anticoagulants (DOACs) is most dependent on renal clearance and is contraindicated if CrCl < 15 mL/min (for NVAF)?
- a. Apixaban
- b. Rivaroxaban
- c. Dabigatran
- d. Warfarin
Answer: c. Dabigatran
11. The “Dosing in Patients with Renal Dysfunction” is a core module in which foundational course?
- a. PHA5132 Principles of Drug Therapy Individualization
- b. PHA5781 Patient Care I
- c. PHA5163L Professional Skills Lab 3
- d. PHA5021C Personal and Professional Development 1
Answer: a. PHA5132 Principles of Drug Therapy Individualization
12. A patient with end-stage renal disease is taking gabapentin. The pharmacist should be concerned about the accumulation of the drug leading to:
- a. Hypertension
- b. Liver failure
- c. Neurotoxicity (e.g., confusion, sedation, myoclonus)
- d. A severe rash
Answer: c. Neurotoxicity (e.g., confusion, sedation, myoclonus)
13. Which of the following drugs has an active metabolite that accumulates in renal dysfunction and can cause seizures?
- a. Morphine
- b. Meperidine
- c. Hydromorphone
- d. Fentanyl
Answer: b. Meperidine
14. A patient is prescribed vancomycin. The dose and frequency are primarily determined by the patient’s:
- a. Liver function and weight.
- b. Renal function and weight.
- c. Age and sex only.
- d. Serum albumin level.
Answer: b. Renal function and weight.
15. A patient with a CrCl of 25 mL/min is prescribed ciprofloxacin 500 mg PO BID (the standard dose). The pharmacist should recommend:
- a. Increasing the dose to 750 mg PO BID.
- b. Continuing the current dose.
- c. Adjusting the dose to 500 mg PO once daily.
- d. Switching to an IV formulation.
Answer: c. Adjusting the dose to 500 mg PO once daily.
16. The curriculum covers drug individualization in dialysis.
- a. True
- b. False
Answer: a. True
17. Which of the following H2-receptor antagonists requires dose adjustment in moderate-to-severe renal impairment?
- a. Famotidine
- b. Omeprazole
- c. Pantoprazole
- d. Lansoprazole
Answer: a. Famotidine
18. Why is nitrofurantoin contraindicated in patients with a CrCl < 60 mL/min (note: some references use lower cutoffs, but it is contraindicated in significant impairment)?
- a. It has a high risk of nephrotoxicity.
- b. It accumulates and causes peripheral neuropathy.
- c. It fails to concentrate in the urine, leading to a lack of efficacy for UTIs.
- d. Both b and c are correct.
Answer: d. Both b and c are correct.
19. A drug’s package insert provides dosing recommendations for renal impairment. A pharmacist should:
- a. Always follow the package insert recommendations exactly.
- b. Use the package insert as a primary guide but apply clinical judgment based on the specific patient.
- c. Ignore the package insert and use a general dosing rule.
- d. Call the manufacturer for every patient.
Answer: b. Use the package insert as a primary guide but apply clinical judgment based on the specific patient.
20. The “Transcending Concept – Pharmacokinetics: Dosing in Renal Dysfunction” is a module in which course?
- a. PHA5784C Patient Care 4
- b. PHA5163L Professional Skills Lab 3
- c. PHA5781 Patient Care I
- d. PHA5782C Patient Care 2
Answer: a. PHA5784C Patient Care 4
21. A patient with CrCl of 40 mL/min is taking digoxin. The maintenance dose should be:
- a. Increased
- b. Decreased
- c. Unchanged
- d. Held
Answer: b. Decreased
22. Which of the following is NOT a reason to adjust a drug dose in renal failure?
- a. The drug is primarily cleared by the kidneys.
- b. The drug has a narrow therapeutic index.
- c. The drug has toxic metabolites that are renally cleared.
- d. The drug is primarily cleared by the liver.
Answer: d. The drug is primarily cleared by the liver.
23. A patient develops acute kidney injury and their SCr is rapidly rising. How does this affect the accuracy of the Cockcroft-Gault equation?
- a. It makes the equation more accurate.
- b. It has no effect on accuracy.
- c. It makes the equation unreliable and likely to overestimate renal function.
- d. It makes the equation underestimate renal function.
Answer: c. It makes the equation unreliable and likely to overestimate renal function.
24. The renal system module in Patient Care 4 covers dosing in renal dysfunction.
- a. True
- b. False
Answer: a. True
25. A patient on hemodialysis requires treatment with an aminoglycoside. The dosing should be:
- a. Based on the patient’s pre-dialysis weight.
- b. Timed to be given after dialysis sessions.
- c. Monitored with pre- and post-dialysis drug levels.
- d. All of the above.
Answer: d. All of the above.
26. Which of the following pain medications is generally considered safer in severe renal impairment?
- a. Morphine
- b. Meperidine
- c. Codeine
- d. Fentanyl
Answer: d. Fentanyl
27. Allopurinol requires dose reduction in CKD because:
- a. Its active metabolite, oxypurinol, is renally cleared and can accumulate.
- b. It is not effective in patients with CKD.
- c. It causes hyperkalemia.
- d. It is highly nephrotoxic.
Answer: a. Its active metabolite, oxypurinol, is renally cleared and can accumulate.
28. An active learning session on the renal system, including dosing, is part of which course?
- a. PHA5784C Patient Care 4
- b. PHA5163L Professional Skills Lab 3
- c. PHA5781 Patient Care I
- d. PHA5782C Patient Care 2
Answer: a. PHA5784C Patient Care 4
29. The first step in determining if a drug needs a dose adjustment is to:
- a. Calculate the creatinine clearance.
- b. Check a reliable drug information resource for the drug’s elimination properties and dosing recommendations.
- c. Call the prescriber.
- d. Ask the patient if they have kidney disease.
Answer: b. Check a reliable drug information resource for the drug’s elimination properties and dosing recommendations.
30. The principle of renal clearance is a major topic in the Drug Therapy Individualization course.
- a. True
- b. False
Answer: a. True
31. For concentration-dependent antibiotics like aminoglycosides, which adjustment method is often used?
- a. Reducing the dose and extending the interval.
- b. Keeping the dose the same to achieve a high peak, but extending the interval significantly.
- c. Giving smaller doses more frequently.
- d. Switching to an oral formulation.
Answer: b. Keeping the dose the same to achieve a high peak, but extending the interval significantly.
32. A patient’s CrCl is calculated to be 25 mL/min. They are prescribed the standard dose of a drug that is 80% renally cleared. What should the pharmacist do?
- a. Dispense the prescription as written.
- b. Contact the prescriber with a recommendation for a dose adjustment.
- c. Refuse to fill the prescription.
- d. Tell the patient to take half of each tablet.
Answer: b. Contact the prescriber with a recommendation for a dose adjustment.
33. Which of these beta-lactam antibiotics does NOT require dose adjustment in renal impairment because it has significant biliary excretion?
- a. Piperacillin
- b. Meropenem
- c. Ceftriaxone
- d. Cefepime
Answer: c. Ceftriaxone
34. The term “uremia” refers to:
- a. The accumulation of waste products in the blood due to kidney failure.
- b. High levels of uric acid.
- c. The presence of urine in the blood.
- d. A type of anemia.
Answer: a. The accumulation of waste products in the blood due to kidney failure.
35. A patient on peritoneal dialysis (PD) has a different dosing consideration than a patient on hemodialysis because:
- a. PD is an intermittent therapy.
- b. PD is a continuous process, leading to a more steady-state clearance of some drugs.
- c. No drugs are cleared by PD.
- d. All drugs are cleared by PD.
Answer: b. PD is a continuous process, leading to a more steady-state clearance of some drugs.
36. A patient is taking lithium and their renal function declines. The pharmacist should monitor for:
- a. Decreased lithium levels.
- b. Increased lithium levels and signs of toxicity (e.g., tremor, confusion).
- c. No change in lithium levels.
- d. Liver toxicity.
Answer: b. Increased lithium levels and signs of toxicity (e.g., tremor, confusion).
37. Which factor is NOT used in the Cockcroft-Gault equation?
- a. Age
- b. Sex
- c. Race
- d. Serum creatinine
Answer: c. Race
38. The pharmacist’s clinical judgment is critical in renal dosing because:
- a. Equations provide an estimate, not a perfect measurement.
- b. The patient’s clinical status (e.g., volume status) can affect drug clearance.
- c. The target for therapy (e.g., serious infection vs. mild infection) can influence dosing decisions.
- d. All of the above.
Answer: d. All of the above.
39. For renally cleared drugs, as CrCl decreases, the drug’s half-life:
- a. Decreases
- b. Stays the same
- c. Increases
- d. Becomes zero
Answer: c. Increases
40. An active learning session on dosing in renal dysfunction is part of which course module?
- a. Module 7: Renal System
- b. Module 1: PUD and GERD
- c. Module 4: Gastrointestinal Infections
- d. Module 5: Nutrition & Weight Management
Answer: a. Module 7: Renal System
41. The risk of bleeding with dabigatran increases significantly with:
- a. Increasing age.
- b. Declining renal function.
- c. Concomitant use of aspirin.
- d. Both a and b.
Answer: d. Both a and b.
42. Which class of drugs can cause an expected, small, and usually acceptable rise in SCr upon initiation?
- a. NSAIDs
- b. ACE inhibitors and ARBs
- c. Loop diuretics
- d. Beta-blockers
Answer: b. ACE inhibitors and ARBs
43. A pharmacist’s daily responsibilities in a hospital often include:
- a. Screening all patient profiles for medications that require renal dose adjustments.
- b. Placing dialysis catheters.
- c. Performing renal ultrasounds.
- d. Writing all prescriptions.
Answer: a. Screening all patient profiles for medications that require renal dose adjustments.
44. A patient taking metformin with a GFR of 35 mL/min/1.73m² should:
- a. Have the dose increased.
- b. Continue the current dose without concern.
- c. Be evaluated to see if the benefit outweighs the risk, possibly with a dose reduction.
- d. Have the metformin stopped immediately.
Answer: c. Be evaluated to see if the benefit outweighs the risk, possibly with a dose reduction.
45. Which of the following is the most important characteristic to consider when dosing a drug in renal failure?
- a. The drug’s color.
- b. The fraction of the drug that is excreted unchanged by the kidneys.
- c. The cost of the drug.
- d. The drug’s formulation.
Answer: b. The fraction of the drug that is excreted unchanged by the kidneys.
46. A drug is 10% renally cleared. In a patient with ESRD, this drug will likely require:
- a. A 90% dose reduction.
- b. A 50% dose reduction.
- c. No significant dose adjustment.
- d. A dose increase.
Answer: c. No significant dose adjustment.
47. A drug is highly protein-bound (98%). Will it be significantly removed by hemodialysis?
- a. Yes, because it is small.
- b. No, because protein-bound drug is not readily filtered by the dialyzer.
- c. Yes, because it is water-soluble.
- d. It depends on the type of dialysis machine.
Answer: b. No, because protein-bound drug is not readily filtered by the dialyzer.
48. An active learning session on renal dosing is part of which course?
- a. PHA5784C Patient Care 4
- b. PHA5163L Professional Skills Lab 3
- c. PHA5781 Patient Care I
- d. PHA5782C Patient Care 2
Answer: a. PHA5784C Patient Care 4
49. When adjusting drug doses, pharmacists must consider:
- a. The specific drug and its pharmacokinetic profile.
- b. The patient’s estimated renal function.
- c. The clinical context and therapeutic goal.
- d. All of the above.
Answer: d. All of the above.
50. The ultimate goal of dose adjustment in renal dysfunction is to:
- a. Make the dosing schedule as simple as possible.
- b. Achieve therapeutic efficacy while minimizing the risk of drug accumulation and toxicity.
- c. Save the healthcare system money.
- d. Use the lowest possible dose of every medication.
Answer: b. Achieve therapeutic efficacy while minimizing the risk of drug accumulation and toxicity.