PHENYTOIN LEVEL, TOTAL AND FREE

Test Code

LAB176

Quest Code

A4294

Includes

Phenytoin, free(3189)

Phenytoin(713)

Preferred Specimen

1 mL Serum collected in a RED-TOP Tube (No Gel)

Patient Preparation
Collect as a trough just prior to next dose. For patients receiving Fosphenytoin therapy, collect as a trough at least 2 hours after IV infusion or at least 4 hours after IM injection.

Minimum Volume

1 mL

Transport Container

Transport tube

Specimen Stability

Room Temperature: 4 Days
Refrigerated: 7 Days
Frozen: 30 Days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Specimen received in Serum Separator Tube

Methodology
Immunoassay

Setup Schedule

Monday-Saturday

Report Available

2-4 days

Last Updated: May 11, 2022

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.