Renal and Hepatic Prescribing Flashcards
7 cards from real PSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Renal and Hepatic Prescribing flashcards as text
A patient with severe hepatic impairment is prescribed warfarin. What change in anticoagulant response is expected compared to a patient with normal liver function?
Answer: INR will be higher than expected, requiring lower doses
Hepatic impairment both reduces clotting factor synthesis and impairs warfarin metabolism, leading to enhanced anticoagulant effect and elevated INR.
Morphine should be used with extreme caution in renal failure primarily due to accumulation of which active metabolite?
Answer: Morphine-6-glucuronide (M6G)
Morphine-6-glucuronide (M6G) is a potent active analgesic metabolite that accumulates in renal failure and can cause profound respiratory depression.
Which formula is the standard method recommended for estimating creatinine clearance when adjusting drug doses in renal impairment?
Answer: Cockcroft-Gault equation
The Cockcroft-Gault equation is the standard formula used for drug dosing calculations in renal impairment as it was validated using drug clearance data.
A patient with CrCl 30 mL/min is prescribed digoxin. Compared to a patient with normal renal function, the expected pharmacokinetic change is:
Answer: Prolonged half-life, requiring dose reduction
Digoxin is 70% renally excreted; in renal impairment, its half-life is prolonged significantly, requiring maintenance dose reduction to prevent toxicity.
Which analgesic should be avoided in renal impairment due to accumulation of its neurotoxic active metabolite, norpethidine?
Answer: Pethidine (meperidine)
Pethidine is metabolized to norpethidine, a neuroexcitatory metabolite that accumulates in renal failure and causes CNS toxicity including seizures.
NSAIDs cause acute kidney injury in patients with renal impairment primarily through which mechanism?
Answer: Inhibition of prostaglandin-mediated afferent arteriolar dilation
NSAIDs inhibit prostaglandins that maintain afferent arteriolar dilation in states of low renal perfusion, reducing GFR and precipitating acute kidney injury.
A patient with Child-Pugh Class B liver disease is prescribed a drug with a high hepatic extraction ratio administered orally. The most likely pharmacokinetic consequence is:
Answer: Increased oral bioavailability due to reduced first-pass metabolism
High hepatic extraction ratio drugs undergo extensive first-pass metabolism; hepatic impairment reduces this extraction, substantially increasing systemic bioavailability.