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Phenobarbital

Item Value
Test Update Information Phenobarbital assay changed from the Abbott Axsym method to the Beckman DxC method on 09/20/2012.
Approval req'd? No
Available Stat? Yes
Test code PBAR
Performed by Parnassus Chemistry
In House Availability Test available 24 hours per day 7 days per week
Method Turbidimetric inhibition immunoassay (Beckman DxC800)
Collection Instructions Time to steady state: 2-4 weeks

Collect sample before next dose.

Indicate time of draw on requisition.
Container type Gold top or Light Green top
Amount to Collect 1 mL blood
Sample type Serum or plasma
Preferred volume 0.5 mL serum or plasma
Min. Volume 0.2 mL serum or plasma
Units mg/L
Normal range Therapeutic levels:
0-17 years 15-40 mg/L
≥ 18 years 10-40 mg/L


Therapeutic ranges adopted or modified from the literature based on recommendations of UCSF Pharmacists
Critical value > 50 mg/L
Synonyms Luminal
Stability Room temperature 8 hours, refrigerated 2 days, frozen at -20C 1 week
Turn around times STAT 1 hour, Routine 4 hours
Additional information See also Barbiturates and Drug Screening.

Click here for A guide on Drug Level Monitoring
LOINC code 3948-7
Last Updated 9/3/2013 3:54:47 PM
Entry Number 735
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