Phenytoin, Free
Also known as: DIL FR
Use
Therapeutic drug management for patients with renal failure or conditions that may alter albumin concentrations. Free phenytoin may be important to monitor in patients with altered or unpredictable protein binding capacity because phenytoin is highly bound at therapeutic concentrations. Phenytoin is also subject to drug-drug interactions due to displacement of protein binding and extensive metabolism. Cross-reactivity with metabolites may account for differences in phenytoin concentrations among analytical methods.
Special Instructions
Not provided.
Limitations
Cross-reactivity with metabolites may account for differences in phenytoin concentrations among analytical methods.
FDA ApprovedNew York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 3969-3 - Phenytoin Free SerPl-mCnc
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
1 mL
Container
Plain red.
Collection Instructions
Separate serum from cells within 2 hours of collection. Transfer serum to an ARUP Standard Transport Tube.
Storage Instructions
Refrigerated.
Causes for Rejection
Citrated plasma. Serum separator tubes (SST). Tubes that contain liquid anticoagulant.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 1 month |
Other tests from different labs that may be relevant