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Lab Manual for UCSF Clinical Laboratories

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Item Value
Approval req'd? No
Available Stat? No
Test code PRIM
Performed by Quest
Sendout? Yes
Method Immunoassay
Collection Instructions Time to steady state: 2-3 days.

A trough levels is ideally drawn < 1 hour before the next dose.

Indicate the time of draw on the requisition.
Container type Red top (Gold top NOT acceptable), Lavender OK
Amount to Collect 4 mL blood
Sample type Serum (EDTA plasma acceptable)
Preferred volume 1 mL serum or plasma
Min. Volume 0.5 mL serum or plasma
UCSF Rejection Criteria Collected in Gold top (SST). Severely icteric, lipemic or hemolyzed samples
Processing notes Centrifuge and immediately separate serum or plasma specimens from the cells into clean, plastic screw-capped vials. Refrigerate. Order Quest test # 751X . If B/T, order LabCorp #007856
Ref Lab Rejection Criteria Severely icteric, lipemic or hemolyzed samples
Units mg/L
Normal range Primidone:
Therapeutic: 5-15 mg/L
Potentially toxic: > 15 mg/L

15.0-40.0 mg/L
Critical value UCSF: > 15 mg/L
Quest Priority-1: > 15 mg/L
Synonyms Mysoline
Stability Room temperature 3 days, refrigerated 2 weeks, frozen at -20C 1 month
Turn around times Test performed Monday-Saturday. Turnaround time: 1-4 days.
Additional information Assay of Primidone levels is accompanied by the measurement of Primidone's major metabolite Phenobarbital, for which Quest considers the adult therapeutic level to be 10-40 mg/L, the pediatric therapeutic level to be 10-30, and the potentially toxic level to be > 40.

Click here for: A Guide on Drug Level Monitoring
CPT coding 80188-90, 80184-90
LOINC code 3978-4
Last Updated 11/16/2014 7:07:16 PM
Entry Number 779
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