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Phenytoin, Free

Test Name:Phenytoin, Free
Epic Order Code:LAB32  
CPT Code:80186  
Specimen(s) Type:Serum  
Acceptable Container(s):Top is red.
Testing Schedule:24 hrs/day, 7 days/week
Turn Around Time:STAT: 1 hour  
 Routine: 2 hours  
Collection Information:No special patient preparation is required. Obtain specimen by standard collection procedures.
Transport Information:Deliver to lab immediately. All specimens must be signed into the laboratory.
Reference Clients:If unable to deliver to the lab within 1 hour, centrifuge the specimen and remove serum from the red cells. Store and transport at 2-8° C. Specimen must be received in the lab within 24 hours.
Causes for Rejection:Improperly labeled, incorrect container, contaminated, insufficient quantity, incorrect/delay in transport.
Reference Range:1.0 - 2.0 µg/mL
 Critical: > 3 µg/mL
Additional Information:Due to the observed cross-reactivity of this assay with fosphenytoin, it is recommended that specimens be collected at least 2 hours after an intravenous dose and at least 4 hours after an intramuscular dose of fosphenytoin.