Test Code VAL VALPROIC ACID
Methodology
Particle-Enhanced Turbidimetric Inhibition Immunoassay (PETINIA)
Valproic acid is an anticonvulsant used in the treatment of epilepsy. This test is helpful in monitoring therapy, determining compliance, and assessing toxicity.
Specimen Requirements
Submit only 1 of the following specimens:
Preferred:
Serum
Serum Gel Tube
Container/Tube: Serum gel tube(s)
Specimen Volume: 1 mL (minimum
volume: 0.5 mL) of serum
Collection Instructions: Draw blood just prior to next dose. Spin down within 4 hours of draw.
Note:
1. Date and time of last dose and time of draw are required.
2. Label specimen appropriately (serum).
Alternate:
Serum
Plain, Red-Top Tube
Container/Tube: Plain, red-top tube(s)
Specimen Volume: 1 mL (minimum
volume: 0.5 mL) of serum
Collection Instructions: Draw blood just prior to next dose. Spin down within 4 hours of draw.
Note:
1. Date and time of last dose and time of draw are required.
2. Label specimen appropriately (serum).
Plasma
Container/Tube: Green-top (lithium heparin) tube(s)
Specimen Volume: 1 mL (minimum volume: .05 mL) of plasma
Collection Instructions: Draw blood just prior to next dose. Spin down within 4 hours of draw.
Note:
1. Date and time of last dose and time of draw are required.
2. Label specimen appropriately (plasma).
Day(s) Test Set Up
Monday through Sunday
Reference Values
Therapeutic concentration: 50-100 µg/mL
Critical concentration (automatic call-back):
<18 Years > 120 µg/mL
≥18 Years > 150 µg/mL
Note:
1. Pediatric patients with generalized or mixed seizure disorders may show improved seizure control with trough concentrations of 100 µg/mL to 200 µg/mL
2. The therapeutic trough serum concentration for treatment of manic episodes associated with bipolar disorder is 50 µg/mL to 125 µg/mL.
Performing Laboratory
Logan Health Medical Center-Chemistry
Test Classification and CPT Coding
80164
Specimen Transport Temperature
Refrigerate