Test Code VALP Valproic acid
Specimen and Container/Tube
Specimen Type: Serum
Preferred Specimen: Red Top
Other Acceptable specimens: None
Volume
Preferred Volume: 0.5 mL
Minimum Volume: 0.2 mL
Specimen Stability
Storage Temperature |
Stability |
Room temperature |
2 days |
Refrigerated |
7 days |
Frozen |
3 months |
Collection Instructions
Collect specimen per standard laboratory collection procedures.
Collect at designated intervals for peak or trough testing.
- Peak level: 30 min after completion of dose
- Trough level: 30 min before next dose
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
Collect specimen per standard collection procedure and send to laboratory immediately.
UCMC Offsite and UC MedLab Outreach Instructions:
- Samples should be centrifuged within 2 hours of collection.
- Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
- Aliquot sample into plastic transport tube containing a minimum of 0.2 mL of specimen.
- Samples must be sent refrigerated at 2-8oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are clotted or grossly hemolyzed.
- Specimens that were transported unspun/whole blood and draw time is greater than 6 hours.
Reference Values
Test |
Age |
Sex |
Reference Range |
Valproic Acid |
All |
All |
50 - 100 μg/mL |
Critical Values
Analyte |
Unit |
Low |
High |
Age |
Valproic Acid |
μg/mL |
N/A |
>200 |
All |
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: 4 hours
Testing Schedule: 24/7
Clinical Indications
Useful for monitoring therapy, assessing compliance and evaluating potential valproic acid toxicity.
Test Components
Valproic acid
Methodology
Homogeneous Enzyme Immunoassay Technique (EMIT) (Roche Diagnostics)
CPT Codes
80164
LOINC Codes
4086-5
Synonyms/Keyword Search
Depakote, VPA, VALP2, VALPROIC.
Additional Information
- Results should always be assessed in conjunction with patient's medical history, clinical examination and other findings.
- Co-administration of other anti-epileptic drugs can significantly affect valproic acid metabolism. Several factors complicate interpretation of valproic acid levels, including time interval between drug administration and blood sampling, the type of seizures treated, albumin concentration and factors affecting albumin binding of valproic acid , and the presence of other anti-epileptic drugs and pharmacologically-active metabolites of valproic acid.
- Collection time varies dependent upon desired measurement of peak or trough values.
Last Review Date
8/19/2024