Optimize drug therapy and monitor patient adherence. Can be ordered when fosphenytoin is administered.
Within 24 hours
Allow serum specimen to clot completely at room temperature to ensure complete clot formation has taken place prior to centrifugation. Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Specimens collected in separator tubes, sodium fluoride, potassium oxalate, EDTA tubes. Hemolyzed specimens.
After separation from cells: Ambient: 8 hours; Refrigerated: 4 days; Frozen: 1 month
0-2 months: 6.0-14.0 µg/mL
Toxic: 14.1 µg/mL or greater
3 months and older: 10.0-20.0 µg/mL
Toxic: 30.1 µg/mL or greater
The therapeutic range for phenytoin applies to non-uremic patients. In critically ill uremic patients who are receiving fosphenytoin, the value reported may be higher than the patient's actual serum concentration due to interfering substances.
|Component Test Code*||Component Chart Name||LOINC|
- Phenytoin, Total, Serum
- Total phenytoin