ARUP's Laboratory Test Directory

Primidone and Metabolite : 0090202

Mnemonic: PRIM

Methodology: Immunoassay
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Collect: Plain red. Also acceptable: Green (sodium heparin).

Specimen Preparation: Allow specimen to clot completely at room temperature. Separate serum from cells within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.8 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Separator tubes.

Stability (collection to initiation of testing): After separation from cells: Ambient: 1 week; Refrigerated: 1 week; Frozen: 1 month
Reference Interval:
 
Test Number Components Reference Interval
0090230Phenobarbital 0-2 months: 15.0-30.0 µg/mL
  Toxic: 40.1 µg/mL or greater 
3 months and older: 15.0-40.0 µg/mL
  Toxic: 50.1 µg/mL or greater
 Primidone5-12 µg/mL

Interpretive Data: Primidone concentrations greater than 15 µg/mL in conjunction with therapeutic levels of phenobarbital may be associated with toxicity. 
CPT Code(s): 80188; 80184
Cross References: Mysoline (Primidone & Metabolite)