NHA Certified Phlebotomy Technician (CPT)Patient PreparationHard
A phlebotomy technician is instructing a patient about a timed blood draw for therapeutic drug monitoring. Which of the following instructions is MOST important for the patient to understand?
- AThe exact time the medication was taken.
- BThe importance of remaining still during the draw.
- CThe need to fast before the blood draw.
- DThe potential side effects of the medication.
Show answer & explanationAnswer & explanation
Correct answer: A. The exact time the medication was taken.
Therapeutic drug monitoring (TDM) requires precise timing of blood collection relative to the last dose of medication to accurately assess drug levels (peak or trough). The exact time of the last dose is critical for interpreting results.
Why the other options are wrong
- B. Remaining still is important for any blood draw but not specific to the unique requirements of timed drug monitoring.
- C. Fasting may be required for some TDM tests, but the exact medication time is universally critical for all TDM draws.
- D. While important for patient care, discussing medication side effects is typically the physician's or nurse's responsibility, not the phlebotomist's primary focus for a timed draw.
Therapeutic Drug Monitoring (TDM)
Measurement of medication concentrations in the blood to optimize drug dosing, assess compliance, and avoid toxicity, requiring precise timing of blood collection.
- Timing relative to last dose is critical.
- Often involves 'trough' (lowest) or 'peak' (highest) levels.
- Used for drugs with narrow therapeutic windows.
Memory trick: Time the dose, time the draw, accurate results for all!