Test Code LAB30 Phenobarbital
Performing Laboratory
Asante Rogue Regional Medical Center / Asante Three Rivers Medical Center
Specimen Minimum Volume
0.5 mL
Billing Code
2050995
Methodology
Particle Enhanced Turbidimetric Inhibition Immunoassay
Specimen Requirements
RRMC:
Lithium Heparin Green top tube
Outpatient clients must draw SST
TRMC:
Plain Red top tube No SST or PST
Collect just prior to next dose, please provide last dose information
Performing Department
Chemistry
Day(s) Test Set Up
Routine – same day
ASAP – 2 hours after receipt of specimen in lab
STAT – 1 hour after receipt of specimen in lab
Test Classification and CPT Coding
80184 - Phenobarbital
Additional Information
Monitor therapeutic drug level of phenobarbital. Phenobarbital is designed to induce prompt and prolonged central nervous system sedation. It is occasionally combined with other drugs such as phenytoin, carbamazepine or valproic acid. When used in conjunction with valproic acid, excretion diminished due to urine acidification by valproic acid. Thus, toxic concentrations of phenobarbital may be encountered in a patient previously doing well on phenobarbital alone if valproic acid is added to the drug regimen.
Specimen Transport Temperature and Stability
Centrifuge and refrigerate within 2 hours of collection
Primary tube: Spun SST stable 24 hours at 2° to 8° C
Serum stable 48 hours if aliquoted and refrigerated at 2° to 8° C
Reasons for Rejection
Icterus
Lipemia
Hemolysis
Quantity not sufficient (QNS)
Lack of Two Patient Identifiers:
1-Patient's First & Last name
2-Patient's Date of Birth