VALPROIC ACID LEVEL, TOTAL

Test Code

LAB24

Quest Code

916

CPT Codes
80164

Preferred Specimen

1 mL serum collected in a red-top tube (no gel)

Patient Preparation
Collect as a trough just prior to next dose

Minimum Volume

0.2 mL

Other Acceptable Specimens

Plasma collected in: EDTA (lavender-top), sodium heparin (green-top), lithium heparin (green-top), sodium fluoride or potassium oxalate (gray-top), or 3.2% sodium citrate (light blue-top) tube

Instructions

Do not use gel barrier tubes. Centrifuge and immediately separate serum or plasma specimens from the cells into clean transport tube.

Transport Container

Transport tube

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 5 days
Refrigerated: 7 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Serum separator tube (SST)

Methodology
Immunoassay (IA)

Setup Schedule

Mon-Sat

Report Available

1-3 days

Reference Range

50.0-100.0 mg/L

Clinical Significance

Valproic acid is used as an anticonvulsant to treat certain types of seizures, to prevent migraine headaches and to treat various psychiatric illnesses such as bipolar disorder and aggression. Drugs that compete for protein-binding sites with valproic acid can increase the concentration of valproic acid. Therapeutic drug monitoring is useful to optimize dose. Measurement of the free concentration is useful if toxicity is suspected.

Performing Laboratory

Quest Diagnostics-Lenexa

10101 Renner Blvd

Lenexa , KS 66219-9752

Last Updated: August 13, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.