Phenytoin (Dilantin)

Test Code

LAB31

Alias/See Also

Dilantin, Phenytoin Level

CPT Codes
80185

Preferred Specimen

4.5 ml (4.5 ml min) lithium heparin (green); alternate-SST (gold) or Red (no additive)

Minimum Volume

2 ml plasma; alternate-serum

Other Acceptable Specimens

Gold SST

Instructions

Separate from cells ASAP. After centrifugation, if not in gel barrier tube, pour off plasma into an aliquot tube

Transport Temperature

Room Temp

Specimen Stability

Separated from cells: 1 month refrigerated

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

Icteric: >30 mg/dL bilirubin, Hemolysis: >800 mg/dL hemoglobin, Lipemia: >750 mg/dL triglycerides

Methodology
Fluorescent Polarization Immunoassay (FPIA), Immunoassay

Setup Schedule

Mon- Sun

Reference Range

Therapeutic: 10.0 – 20.0 ug/mL
Toxic: >/= 30.0 ug/mL

Clinical Significance

Phenytoin
is used in the treatment of primary or secondary generalized tonic-clonic seizures (whole brain seizures), simple
partial (focal cortical seizures), or complex partial seizures (temporal lobe seizures), and epilepsy.

Performing Laboratory
Piedmont Athens Regional

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.