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Test Code LAB172 Valproic Acid, Free and Total, Serum

Useful For

Monitoring both total and free valproic acid levels in therapy

 

Assessing compliance

 

Evaluating potential toxicity

Profile Information

Test ID Reporting Name Available Separately Always Performed
VALPF Valproic Acid, Free, S Yes Yes
VALPA Valproic Acid, Tot, S Yes Yes

Method Name

VALPA: Immunoassay

VALPF: Ultrafiltration Followed by Immunoassay

Reporting Name

Valproic Acid, Free and Total, S

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject

Reference Values

VALPROIC ACID, TOTAL

Therapeutic: 50 (trough)-125 (peak) mcg/mL

Critical value: ≥151 mcg/mL

 

VALPROIC ACID, FREE

Therapeutic: 5-25 mcg/mL

Critical value: >30 mcg/mL

Cautions

Specimens subjected to significant heat or other factors that could cause protein denaturation would demonstrate an artificially increased free valproic acid.

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

VALPA-80164

VALPF-80165

LOINC Code Information

Test ID Test Order Name Order LOINC Value
VALPG Valproic Acid, Free and Total, S 57775-9

 

Result ID Test Result Name Result LOINC Value
VALPF Valproic Acid, Free, S 4087-3
VALPA Valproic Acid, Tot, S 4086-5

NY State Approved

Yes

Forms

If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.

Secondary ID

37067

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.