FREE PHENYTOIN, serum (087-0551)
Synonyms: Free Dilantin
CPT 4 Code: 80186
Test Order Mnemonic: PHENY FREE
Lab: Clinical Chemistry
Request Form: Special Chemistry Form 2
Collection: Routine venipuncture; immediately before
the next dose
Storage Instructions: Store blood at room
temperature or refrigerated at 2-8°C. Centrifuge the specimen to remove the serum from
the red cells within 4 hours of collection and store serum refrigerated.
Causes for Rejection: Blood collected in SST/gel
separator tubes, heparinized blood
Availability: Samples are received 24 hours per day
at Sample Management, Room 5.136 McCullough.
Turnaround Time: Routine: 24 hours; STAT: 1 hours
Specimen: Blood
Volume: 3 mL blood
Minimum Volume: 0.5 mL serum
Container: Red-topped tube. Do not use
SST/gel separator tubes.
Reference Ranges: Therapeutic Range: 1 – 2
mcg/mL
Critical Values: Potential toxic: >2.5 mcg/mL
Test Method: FPIA
Reviewed/revised April 2007 by P. Harris
