Phenobarbital, Serum
Use
Phenobarbital is used as a central nervous system suppressant to control generalized and partial seizures. It is often coadministered with other drugs for complex seizure disorders. Monitoring the therapeutic concentration of phenobarbital is crucial to ensure efficacy while preventing toxicity. It is particularly useful in assessing patient compliance with medication regimens or detecting possible overdose scenarios, as toxicity can lead to sedation, reduced respiratory function, and potentially life-threatening situations.
Special Instructions
Not provided.
Limitations
The test is effective in tracking phenobarbital levels, but it does not account for drug interactions affecting other medications metabolized through the hepatic cytochrome P450 pathway. Acute intermittent porphyria might be induced by phenobarbital, leading to attacks due to stimulation of the cytochrome P450 system. Typical cautionary measures should be observed if incompatible specimen types are submitted, as they may cause the specimen to be rejected.
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
Phenobarbital
Analyte
LOINC Codes
- 3948-7 - Phenobarb SerPl-mCnc
- 3948-7 - Phenobarb SerPl-mCnc
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.25 mL
Container
Plastic vial
Collection Instructions
Serum gel tubes should be centrifuged within 2 hours of collection. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 28 days |