Phenobarbital, Free
Test Mnemonic
PHENFR
CPT Codes
- 80184 - QTY (1)
Aliases
- Luminal
- Phenobarb,Unbound
Includes
- Phenobarbital - Unbound
Performing Laboratory
LabCorp
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Plasma | Sodium or Lithium heparin (Green) | Refrigerated | Gel-barrier tubes are not recommended. Separate plasma from cells within 2 hours of collection and transfer to standard aliquot tube. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 3 mL | Serum | No additive (Red) | Gel-barrier tubes are not recommended. Separate serum from cells within 2 hours of collection and transfer to standard aliquot tube. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1.2 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | After separation from cells: 72 hours |
| Refrigerated | After separation from cells: Acceptable |
| Frozen | After separation from cells: Acceptable |
Days Performed
Varies
Turnaround Time
4 - 8 days
Methodology
| Name | Description |
|---|---|
| Immunoassay (IA) | |
| Ultrafiltration (ULT) |
Reference Range
| Phenobarbital, Free | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Normal | 6.0 - 20.0 | ug/mL | Urgent | > / = 25.0 | ug/mL |
Special Info
Gel barrier tubes are not recommended.
Clinical Info
This test is useful for therapeutic drug management. Trough levels are most reproducible.