American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

What is an important consideration when collecting a trough specimen for drug monitoring?

1. Timing of the collection

2. Volume of the blood sample

3. Type of collection tube used

4. Temperature at which specimen is placed

The correct answer is: Timing of the collection

When collecting a trough specimen for drug monitoring, timing of the collection is crucial. A trough specimen is typically collected just before the next dose of the medication is administered. This timing ensures that the level of the drug in the blood is at its lowest point, allowing healthcare providers to assess whether the drug concentration is within the therapeutic range or if adjustments are necessary. Correctly timing the collection can significantly impact the accuracy of the monitoring and subsequent decisions regarding the patient's treatment plan. While factors like blood sample volume, type of collection tube, and specimen temperature can be important in ensuring integrity and stability of the sample, they do not hold the same weight as timing does in the context of trough level determination. Properly timing the specimen collection is what ultimately ensures the monitoring is reflective of the drug's pharmacokinetics.