Phenytoin, Total : 713

Test Code
PTNT or 713

Alias/See Also
Dilantin; Hydantoin

CPT Codes

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.

Plain red. Also acceptable: lavender (EDTA), green (no gel) (sodium heparin) tube, or green (no gel) (lithium heparin) tube.

Transport Container
Centrifuge plain red, lavender, or green tube and aliquot 1 mL (Min: 0.2 mL) serum or plasma into a standard transport tube.

Transport Temperature

Specimen Stability
After separation from cells: Ambient: 5 days; Refrigerated: 10 days; Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Serum separator tube.

Immunoassay (IA)

Setup Schedule

Report Available
1-4 days (From receipt at performing laboratory)

Reference Range
10.0-20.0 mg/L

Clinical Significance
Phenytoin is an anticonvulsant hydantoin used for the treatment of generalized tonic-clonic (grand mal) and complex partial seizures. Phenytoin is also used for prophylaxis in neurosurgical procedures. Phenytoin levels are monitored to assure adequate therapeutic levels are achieved and to avoid toxicity.

Performing Laboratory
Quest Diagnostics

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.