FPGEE FPGEE Exam 2

Question 1

Which cytochrome P450 enzyme is primarily responsible for the metabolism of warfarin's S-enantiomer?

Accepted Answer

CYP2C9

Answer

CYP2C9 metabolizes the more pharmacologically active S-warfarin, which is why CYP2C9 polymorphisms and inhibitors significantly affect warfarin dosing.

Question 2

A patient with CrCl of 25 mL/min requires anticoagulation. Which agent would be MOST appropriate to avoid with severe renal impairment?

Accepted Answer

Dabigatran

Answer

Dabigatran is approximately 80% renally excreted and is contraindicated in severe renal impairment (CrCl <15 mL/min) and requires dose adjustment at lower CrCl values.

Question 3

Which pharmacokinetic parameter describes the fraction of an administered drug dose that reaches systemic circulation unchanged?

Accepted Answer

Bioavailability

Answer

Bioavailability (F) represents the fraction of the administered dose that reaches the systemic circulation in active form, accounting for absorption and first-pass metabolism.

Question 4

A patient taking rifampin for tuberculosis starts oral contraceptives. What counseling is MOST important?

Accepted Answer

Use additional barrier contraception because rifampin is a strong CYP inducer

Answer

Rifampin is a potent CYP3A4 inducer that significantly increases the metabolism of oral contraceptive hormones, reducing their efficacy and requiring additional contraception.

Question 5

Which buffer system is the PRIMARY extracellular buffer in human blood?

Accepted Answer

Bicarbonate-carbonic acid system

Answer

The bicarbonate-carbonic acid buffer system is the primary extracellular buffer, accounting for about 80% of the total blood buffering capacity.

FPGEE Exam Practice Test

FPGEE Exam Practice Test

FPGEE FPGEE Exam 2