PSA PSA Therapeutic Drug Monitoring

Question 1

Which of the following drugs requires routine therapeutic drug monitoring (TDM) due to its narrow therapeutic index?

Accepted Answer

Vancomycin

Answer

Amoxicillin

Answer

Azithromycin

Answer

Metformin

Question 2

A patient on digoxin has a serum level of 2.8 ng/mL. The therapeutic range is 0.5–2.0 ng/mL. What is the most appropriate next step?

Accepted Answer

Hold digoxin and reassess

Answer

Increase the digoxin dose

Answer

Continue the current dose

Answer

Switch to a different cardiac glycoside

Question 3

When should a trough level for vancomycin be drawn to accurately reflect steady-state concentrations?

Accepted Answer

Immediately before the next dose

Answer

30 minutes after the infusion ends

Answer

2 hours after the infusion starts

Answer

At any random time during therapy

Question 4

Which pharmacokinetic parameter is most important when interpreting TDM results for aminoglycosides?

Accepted Answer

Peak and trough levels

Answer

Half-life only

Answer

Volume of distribution only

Answer

Protein binding percentage

Question 5

A patient on phenytoin has a total level of 8 mcg/mL (therapeutic 10–20 mcg/mL) but appears clinically stable. Their albumin is 2.0 g/dL. What should you consider?

Accepted Answer

Check free phenytoin level before adjusting

Answer

Increase phenytoin dose immediately

Answer

Discontinue phenytoin

Answer

Switch to levetiracetam without further testing

Question 6

Which of the following is the primary reason for performing TDM for lithium?

Accepted Answer

Lithium toxicity can be life-threatening and its therapeutic window is narrow

Answer

Lithium has poor oral bioavailability

Answer

Lithium is rapidly metabolized by the liver

Answer

Lithium causes severe allergic reactions