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Phenobarbital

Tube Type = Blue Top or Red Bullet

Tube Type

Test ID LAB30
EPIC Order PHENOBARBITAL LEVEL
CPT Code(s) 80184
Group/Individual Test Individual
Laboratory Core Laboratory
Tube Station STAT: 888; Routine: 30
Specimen Routine: 2 mL blood/navy blue plain tube/red plain tube also acceptable; See Comments
Micro: 300 µL blood/red plain pediatric bullet; See Comments
Stability
Unspun - 4 hrs
Spun and Separated Room Temp - 8 hrs
Spun and Separated Refrigerated - 2 days
Spun and Separated Frozen - 30 days
Availability 24 hrs/day
Turnaround Time Routine: 2 hours; STAT: 1 hour
Reference Range Therapeutic: 15-40 µg/mL (trough)
Toxic: >50 µg/mL
Comments
  • Collection information: Red Top Pediatric Tubes must NOT contain Serum Separator Gel.
  • Trough samples are used for routine monitoring; collect sample immediately before next dose.

Reviewed by J. Carr on January 09, 2026

UNC Hospitals
McLendon Clinical Laboratories
101 Manning Drive
Chapel Hill, NC 27514