Phenobarbital

Message

Performing Lab: Lakeview, Regions

Test Code

0203

Alias/See Also

Sunquest: PBARB

CPT Codes
80184

Includes

Time of Last Dose, Phenobarbital

Preferred Specimen

0.5 mL Lithium Heparin Plasma (light green-top) tube

Minimum Volume

0.2 mL

Other Acceptable Specimens

Serum (gold-top, red-top, red/gray-top), Lithium Heparin (light green-top) on ICE

Instructions

Ordering:
If Free Phenobarbitol is also requested, also order PBRF to Quest

Transport Temperature

Refrigerated

Specimen Stability

Refrigerated: 1 month
Frozen: 3 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross Icterus

Methodology
Enzyme Immunoassay (EIA)

Setup Schedule

Daily

Report Available

Same day.

Reference Range

10 - 40 µg/mL

Critical: >= 50 µg/mL

Clinical Significance

Monitoring serum phenobarbital concentrations, along with careful clinical assessment, is the most effective means of improving seizure control, reducing the risk of toxicity, and minimizing the need for additional anticonvulsant medication. Serum phenobarbital concentrations correlate better with concentration in the brain than does dosage once steady state is reached. Patients taking the same dosage of phenobarbital show considerable variation in serum phenobarbital concentrations because of individual differences in absorption, metabolism, disease states, and compliance. Serum level monitoring helps physicians individualize dosage regimens.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.