SIM

18401 

CPT

80186 

Synonyms

Free Dilantin®; Free Phenytek® Dilantin-125 

Specimen Type

Serum or plasma 

Container

Red-top, lavender-top, or green top (sodium heparin) tube

Collection Instructions

Do not use gel barrier tubes

Volume

Volume: 3 ml. 
Minimum volume: 1.5 ml. 

Additional Information

Phenytoin is 90% bound, but only free fraction circulates through plasma membranes and is biologically active.

Patient Preparation

Specimen Processing Instructions

 Once in the lab,separate serum from cells and transfer to aliquot tube.

Transport Requirements

Room Temperature or Refrigerated

Specimen Stability

 Room Temperature or Refrigerated :14 days 

Rejection Criteria

Gel-barrier tube, hemolysis, lipemia

Reference Range

Reference range accompanies report

Critical Value

Test Includes

Free phenytoin level 

Methodology

Ultrafiltrate assayed by immunoassay 

Testing Frequency

LCA

070763 

Reviewed By

Lisa McBride                  

Reviewed Date

2/20/2018

Supplemental