Renal dialysis: drug dosing and monitoring MCQs With Answer

Introduction: Renal dialysis: drug dosing and monitoring MCQs With Answer is designed for M.Pharm students to build practical competence in managing medications for patients undergoing dialysis. This collection focuses on pharmacokinetic principles that govern drug removal by hemodialysis, peritoneal dialysis and continuous renal replacement therapies, and on clinical strategies for dose adjustment and therapeutic drug monitoring. Emphasis is placed on drug properties (molecular weight, protein binding, volume of distribution), dialysis modality effects, timing of administration, and laboratory monitoring to optimize efficacy and minimize toxicity. The questions mimic real-world decisions pharmacists face in dialysis units and aim to strengthen evidence-based dosing skills.

Q1. Which combination of drug properties most strongly predicts efficient removal by conventional hemodialysis?

• High molecular weight, high protein binding, large volume of distribution, lipophilic
• Low molecular weight, low protein binding, small volume of distribution, water-soluble
• High molecular weight, low protein binding, large volume of distribution, hydrophilic
• Low molecular weight, high protein binding, large volume of distribution, lipophilic

Correct Answer: Low molecular weight, low protein binding, small volume of distribution, water-soluble

Q2. How does high plasma protein binding affect a drug’s dialyzability during hemodialysis?

• It increases dialyzability because proteins facilitate transfer across the membrane
• It decreases dialyzability because the bound fraction is not freely filtered
• It has no effect; only molecular weight matters
• It makes the drug more likely to be removed by peritoneal dialysis but not hemodialysis

Correct Answer: It decreases dialyzability because the bound fraction is not freely filtered

Q3. What does Kt/V measure in the context of dialysis adequacy?

• The ratio of dialyzer membrane surface area to patient body weight
• The product of dialyzer clearance (K) and time (t) divided by volume of distribution of urea (V)
• The percentage of drug removed per dialysis session
• The concentration of uremic toxins in dialysate

Correct Answer: The product of dialyzer clearance (K) and time (t) divided by volume of distribution of urea (V)

Q4. Which antibiotic is most likely to be significantly removed by conventional intermittent hemodialysis?

• Vancomycin
• Gentamicin
• Fluconazole
• Clindamycin

Correct Answer: Gentamicin

Q5. When should vancomycin levels be measured in a patient on intermittent hemodialysis to guide dosing?

• Randomly during dialysis
• Immediately post-dialysis only
• Pre-dialysis (trough) levels, with AUC-based monitoring when possible
• Only once weekly regardless of dialysis timing

Correct Answer: Pre-dialysis (trough) levels, with AUC-based monitoring when possible

Q6. What is the preferred timing for administering antibiotics that are significantly removed by hemodialysis?

• 30 minutes before dialysis
• During the dialysis session
• Immediately after dialysis session
• Timing does not matter

Correct Answer: Immediately after dialysis session

Q7. How does a large volume of distribution (Vd) affect removal of a drug by dialysis?

• Large Vd increases dialysis clearance because more drug is in plasma
• Large Vd decreases dialysis removal because most drug is sequestered in tissues
• Large Vd only affects peritoneal dialysis removal, not hemodialysis
• Large Vd has no predictable effect on dialysis removal

Correct Answer: Large Vd decreases dialysis removal because most drug is sequestered in tissues

Q8. In continuous renal replacement therapy (CRRT), what does the sieving coefficient represent?

• The ratio of drug concentration in ultrafiltrate to plasma concentration
• The membrane surface area divided by blood flow rate
• The time required to clear 50% of a drug
• The patient’s residual renal function

Correct Answer: The ratio of drug concentration in ultrafiltrate to plasma concentration

Q9. Which statement about lithium and dialysis is correct?

• Lithium is poorly dialyzable and dialysis is rarely useful in toxicity
• Lithium is effectively removed by hemodialysis and dialysis is indicated for severe toxicity
• Lithium is removed only by peritoneal dialysis but not by hemodialysis
• Lithium removal by dialysis depends solely on protein binding

Correct Answer: Lithium is effectively removed by hemodialysis and dialysis is indicated for severe toxicity

Q10. What is true about digoxin removal by hemodialysis?

• Digoxin is readily removed by hemodialysis and is used to treat overdose
• Digoxin is not significantly removed by dialysis due to large volume of distribution and tissue binding
• Digoxin is removed only by high-flux dialyzers but not by low-flux
• Digoxin removal is determined solely by its molecular weight

Correct Answer: Digoxin is not significantly removed by dialysis due to large volume of distribution and tissue binding

Q11. In patients with hypoalbuminemia and renal failure, how should phenytoin be monitored?

• Measure total phenytoin concentration only
• Measure free (unbound) phenytoin concentration because total levels can be misleading
• Do not monitor levels; dose by clinical response only
• Increase phenytoin dose empirically since hypoalbuminemia reduces activity

Correct Answer: Measure free (unbound) phenytoin concentration because total levels can be misleading

Q12. Which advantage does CRRT offer over intermittent hemodialysis regarding drug clearance?

• CRRT produces intermittent large swings in drug plasma levels
• CRRT provides continuous, slower solute removal affecting steady-state drug clearance
• CRRT eliminates the need for therapeutic drug monitoring
• CRRT has no impact on dosing considerations compared with intermittent HD

Correct Answer: CRRT provides continuous, slower solute removal affecting steady-state drug clearance

Q13. What is the recommended approach for aminoglycoside dosing in a patient on intermittent hemodialysis?

• Give standard thrice-daily dosing without adjustment
• Give a single daily dose immediately before dialysis
• Administer the dose after dialysis and monitor serum levels to guide interval
• Avoid therapeutic drug monitoring as levels are unreliable in dialysis

Correct Answer: Administer the dose after dialysis and monitor serum levels to guide interval

Q14. Which statement regarding warfarin and hemodialysis is correct?

• Warfarin is substantially removed by hemodialysis and doses must be increased
• Warfarin is not removed by dialysis; dosing is guided by INR rather than dialysis clearance
• Warfarin is removed by peritoneal dialysis but not hemodialysis
• Warfarin dosing should be stopped on dialysis days due to accumulation

Correct Answer: Warfarin is not removed by dialysis; dosing is guided by INR rather than dialysis clearance

Q15. How are erythropoiesis-stimulating agents (ESAs) typically administered in maintenance hemodialysis patients?

• Orally once daily with meals
• Intravenously during dialysis sessions with monitoring of hemoglobin and iron stores
• Topically at the vascular access site
• They are contraindicated in dialysis patients

Correct Answer: Intravenously during dialysis sessions with monitoring of hemoglobin and iron stores

Q16. Which anticoagulation strategy is commonly used during standard intermittent hemodialysis?

• Systemic warfarin infusion during each session
• Unfractionated heparin bolus and infusion; regional citrate anticoagulation used when bleeding risk is high
• No anticoagulation is ever used during dialysis
• Direct oral anticoagulants (DOACs) are infused into the extracorporeal circuit

Correct Answer: Unfractionated heparin bolus and infusion; regional citrate anticoagulation used when bleeding risk is high

Q17. Which drug property enhances removal by peritoneal dialysis compared with retention?

• High lipid solubility and high protein binding
• Low molecular weight and low protein binding
• Large volume of distribution and high tissue binding
• High molecular weight and high degree of ionization

Correct Answer: Low molecular weight and low protein binding

Q18. How does use of a high-flux dialyzer affect vancomycin during intermittent hemodialysis?

• High-flux dialyzers do not affect vancomycin removal
• High-flux dialyzers can remove vancomycin significantly; post-dialysis redosing may be required
• High-flux dialyzers permanently inactivate vancomycin
• High-flux dialyzers increase vancomycin protein binding

Correct Answer: High-flux dialyzers can remove vancomycin significantly; post-dialysis redosing may be required

Q19. What is the most appropriate monitoring strategy to detect drug toxicity in a dialysis patient on multiple renally cleared drugs?

• Rely solely on routine dosing schedules without laboratory checks
• Measure specific drug plasma concentrations when available and monitor renal function, electrolytes and clinical signs of toxicity
• Stop all renally cleared drugs empirically to prevent toxicity
• Use only symptom questionnaires without laboratory testing

Correct Answer: Measure specific drug plasma concentrations when available and monitor renal function, electrolytes and clinical signs of toxicity

Q20. Which oral anticoagulant is known to be dialyzable and may require removal by hemodialysis in overdose?

• Warfarin
• Apixaban
• Dabigatran
• Rivaroxaban

Correct Answer: Dabigatran

Download