|
Test Code
|
|
FRPH
|
|
Test Name
|
|
Phenytoin, Free
|
|
CPT Codes
|
|
80186
|
|
Expected Turnaround Time
|
|
Same day
|
|
Clinical Utility
|
|
The Phenytoin that circulates in blood is 90% protein bound under normal circumstances. Since neurologic activity and toxicity of Phenytoin are directly related to the unbound fraction of the drug, measurement of the free or unbound drug may be necessary where altered protein binding is possible, such as in hypoalbuminemia, pregnancy, renal or hepatic failure, the elderly or use of concomitant drug therapy.
|
|
Specimen and Container Info
|
Specimen | Container | Volume | Serum | Red Top, Plain | 3 mL | Plasma | Dark Green Top (Lithium Heparin) | 3 mL |
|
|
Processing and Submission Instructions
|
- Centrifuge specimens for 5 minutes at 3000 rpm.
- Transfer serum or plasma to a plastic aliquot tube.
|
|
Transport Instructions
|
Transport to the laboratory refrigerated. |
|
Stability Requirements
|
|
|
|
Causes for Rejection
|
- Specimens collected in separator tubes will be rejected.
- Serum/Plasma volumes less than 1mL will be rejected.
|
|
Methodology
|
|
Enzyme Immunoassay (EIA)
|
|
Reference Intervals
|
Age | Reference Interval | Units | All Ages | 1.0 - 2.0 | µg/mL |
|
|
Critical Values
|
Age | Critical Value | Units | All Ages | >=3.0 | µg/mL |
|
|
Performing Location
|
|
Roble Road Core Laboratory
|
|
Alternate Names
|
- Dilantin
- Diphenylhydantoin
- Phenytek
|
|
Testing Schedule
|
|
Routine daily, STAT testing available
|