Test Code LAB4160 PHENOBARBITAL LEVEL
Specimen Type
Preferred Sample: Lithium Heparin Plasma (Mint Green Top, Dark Green Top)
Alternative Sample: Serum (SST, Gold, Corvac, Tiger, Red Top Tube) EDTA Plasma (lavender Top)
Collection Instructions
Draw just prior to next dose. Note times of dose and drawing.
Specimen Volume
1 mL
Minimum Volume
0.5 mL
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Sample Stability
Room Temp: 7 days
Refrigerated: 6 months
Frozen: 6 months
Method
Colorimetric
Reference Ranges
Phenobarbital µg/mL
Therapeutic: 15.0-40.0
Toxic: Greater than 50.0
Reporting Limit
2.0 - 131.3 ug/mL
Synonyms
Luminal
Test Components
Phenobarbital, µg/mL.
CPT Codes
80184
Limitations
Studies have shown that therapeutic drug levels may be altered in serum/plasma that remains in contact with separator gel. Therapeutic drug levels collected in an SST or PST should be run wtihin 24 hours of collection.