Sign in →

Test 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, S

Specimen Type

Serum
Serum 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 Special Container
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

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

80184-Phenobarbital

80185-Phenytoin, total

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PNYG Phenytoin, Tot and Phenobarbital, S 104596-2

 

Result ID Test Result Name Result LOINC Value
PBR Phenobarbital, S 3948-7
PNYA Phenytoin, Total, S 3968-5

Forms

If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.