Lab Test

Valproic Acid, Free

Depakene®, Depakote®, Valproate, Valproex®

Test Codes

Mayo: VALPF, EPIC: LAB6173, Beaker: XVALF

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.

Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 1.0 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 1.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 72 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 28 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN.

Performed

Sunday – Saturday.
Results available within 2-3 days.

Reference Range

By report.

Test Methodology

Ultrafiltration Followed by Immunoassay.

Interpretation

Free valproic acid may be important to monitor in patients with altered or unpredictable protein binding capacity because valproic acid exhibits variable, dose-dependent protein binding. Valproic acid is also subject to drug-drug interactions due to displacement of protein binding. Calculating percent free attempts to minimize differences in assay cross-reactivity and may be useful in dose optimization.

CPT Codes

80165
LOINC:  4087-3, Last Dose Date  29742-4, Last Dose Time  29637-6

Contacts

Last Updated

7/19/2021

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