Test Code DIL Dilantin
Additional Codes
Epic: LAB31
Specimen Required
Specimen Type: Serum
Collection Container/Type
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 3.5 mL
Collection Instructions:
-
Centrifuge and separate cells after clot formation and within 1 hours of collection.
Specimen Minimum Volume
0.5 mL
Specimen Stability
Room temperature: 2 days
Refrigerated: 8 days
Frozen: 5 months
Reference Range
Theraputic range: 10.0 - 20.0 µg/mL
Rejection Due To
Unlabeled, mislabeled, wrong tube type, QNS, grossly hemolyzed.
Report Available
Same day
Clinical Significance
Phenytoin (Dilantin) is one of the most widely prescribed anticonvulsants and is occasionally used as a myocardial antiarrhythmic. In the treatment of epilepsy, phenytoin is indicated for grand mal epilepsy (major motor) and cortical focal seizures and temporal lobe epilepsy.
The main pathway (about 90%) for disposition of phenytoin is by excretion in the urine. It is hydroxylated in the liver and eliminated. The metabolic conversion to HPPH is a saturable process and in many cases small increments in dosage can cause a large increase in phenytoin plasma level. Because of the narrow therapeutic index and the wide inter-individual variability in the rate of phenytoin metabolism and clearance, the determination of blood levels of phenytoin for patients receiving therapy is appropriate.
Method Name
Chemiluminescent Microparticle Immunoassay (CMIA)
Aliases
Phenytoin
Day(s) Performed
Daily