PSA Therapeutic Drug Monitoring Flashcards
6 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 6 PSA Therapeutic Drug Monitoring flashcards as text
A patient on carbamazepine develops diplopia, dizziness, and ataxia. Their carbamazepine level is 15 mcg/mL (therapeutic 4–12 mcg/mL). What is the most likely explanation?
Answer: Carbamazepine toxicity from supratherapeutic levels
Diplopia, dizziness, and ataxia are classic signs of carbamazepine toxicity, consistent with this supratherapeutic level.
Which factor would most likely reduce the accuracy of a TDM result for a narrow therapeutic index drug?
Answer: Drawing blood from the same IV line used for drug infusion
Drawing blood from the same IV line used for the infusion can contaminate the sample with residual drug, falsely elevating the result.
A patient's valproic acid level is 55 mcg/mL (therapeutic 50–100 mcg/mL) but seizures are not controlled. What is the best next step?
Answer: Increase the valproic acid dose toward the upper therapeutic range
Since the level is at the lower end of the therapeutic range and seizures persist, increasing the dose toward the upper range is appropriate before switching agents.
Which of the following best describes the goal of area under the curve (AUC)-guided vancomycin dosing compared to traditional trough-only monitoring?
Answer: AUC dosing better balances efficacy and nephrotoxicity risk
AUC-guided dosing optimizes the AUC/MIC ratio for efficacy while minimizing nephrotoxicity risk compared to trough-only monitoring.
A patient is started on amiodarone while already taking digoxin. Why is TDM particularly important in this scenario?
Answer: Amiodarone inhibits P-glycoprotein and increases digoxin levels
Amiodarone inhibits P-glycoprotein–mediated digoxin elimination, leading to elevated digoxin levels and increased toxicity risk.
In a patient with renal impairment, how does decreased kidney function typically affect the TDM strategy for renally cleared drugs with narrow therapeutic indices?
Answer: Reduce the dose or extend the dosing interval to avoid accumulation
Renal impairment decreases clearance of renally eliminated drugs, requiring dose reduction or interval extension to prevent toxic accumulation.