Home
HelpOrder Code PNYG Phenytoin, Total and Phenobarbital Group, Serum
Useful For
Monitoring for appropriate therapeutic concentration of phenytoin and phenobarbital
Assessing compliance or toxicity
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PNYA | Phenytoin, Total, S | Yes | Yes |
| PBR | Phenobarbital, S | Yes | Yes |
Method Name
Kinetic Interaction of Microparticles in a Solution (KIMS)Reporting Name
Phenytoin, Tot and Phenobarbital, SSpecimen Type
SerumSerum Red
Specimen Required
One serum specimen (0.5 mL of serum) may be sent if using a red top tube.
Serum for Phenytoin:
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Serum for Phenobarbital:
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Serum gel tubes should be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.
Specimen Minimum Volume
0.25 mL for 2 specimens; 0.25 mL for 1 serum red top
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 14 days |
| Frozen | 28 days | |
| Ambient | 72 hours | |
| Serum Red | Refrigerated (preferred) | 7 days |
| Frozen | 14 days | |
| Ambient | 7 days |
Reject Due To
| Gross hemolysis | Reject |
Reference Values
PHENYTOIN, TOTAL
Therapeutic: 10.0-20.0 mcg/mL
Critical value: ≥30.0 mcg/mL
PHENOBARBITAL
Therapeutic: 10.0-40.0 mcg/mL:
Critical value: ≥60.0 mcg/mL
Method Description
Phenytoin, Total:
The assay is based on the kinetic interaction of microparticles in a solution (KIMS). Phenytoin antibody is covalently coupled to microparticles and the drug derivative is linked to a macromolecule. The kinetic interaction of microparticles in solutions is induced by binding of drug-conjugate to the antibody on the microparticles and is inhibited by the presence of phenytoin in the sample. A competitive reaction takes place between the drug conjugate and phenytoin in the serum sample for binding to the phenytoin antibody on the microparticles. The resulting kinetic interaction of microparticles is indirectly proportional to the amount of drug present in the sample.(Package insert: Roche Phenytoin reagent, Roche Diagnostic Corp, Indianapolis, IN)
Phenobarbital:
The assay is based on the kinetic interaction of microparticles in a solution (KIMS). Phenobarbital antibody is covalently coupled to microparticles and the drug derivative is linked to a macromolecule. The kinetic interaction of microparticles in solutions is induced by binding of drug-conjugate to the antibody on the microparticles and is inhibited by the presence of phenobarbital in the sample. A competitive reaction takes place between the drug conjugate and phenobarbital in the serum sample for binding to the phenobarbital antibody on the microparticles. The resulting kinetic interaction of microparticles is indirectly proportional to the amount of drug present in the sample.(Package insert: Roche Phenobarbital reagent, Roche Diagnostic Corp, Indianapolis, IN)
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80184-Phenobarbital
80185-Phenytoin, total
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.