PSA Renal and Hepatic Prescribing

Question 1

A patient with CrCl 20 mL/min requires gentamicin therapy. What is the most appropriate dose adjustment strategy?

Accepted Answer

Reduce dose and extend the dosing interval

Answer

In renal impairment, aminoglycosides require dose reduction and extended dosing intervals to prevent accumulation and nephrotoxicity/ototoxicity.

Question 2

Which of the following drugs does NOT typically require dose reduction in renal impairment?

Accepted Answer

Rifampicin

Answer

Rifampicin is primarily hepatically metabolized and excreted in bile, so it does not require dose reduction in renal impairment.

Question 3

A patient with Child-Pugh Class C cirrhosis requires sedation. Which benzodiazepine is most appropriate?

Accepted Answer

Lorazepam

Answer

Lorazepam undergoes direct glucuronidation rather than hepatic oxidative metabolism, making it safer in severe liver disease where CYP450 activity is impaired.

Question 4

Which opioid is considered relatively safest for analgesia in a patient with severe renal impairment (eGFR <15 mL/min)?

Accepted Answer

Fentanyl

Answer

Fentanyl is metabolized to inactive metabolites that are not significantly renally excreted, making it safer than morphine or codeine in severe renal impairment.

Question 5

A patient with stage 4 CKD (eGFR 20 mL/min) is currently taking metformin for type 2 diabetes. What is the most appropriate action?

Accepted Answer

Stop metformin immediately

Answer

Metformin is contraindicated when eGFR falls below 30 mL/min due to the risk of potentially fatal lactic acidosis from drug accumulation.

(PSA) Prescribing Safety Assessment Practice Test

(PSA) Prescribing Safety Assessment Practice Test

PSA Renal and Hepatic Prescribing