Valproic Acid, Free and Total (Sendout)
General Information
- Lab Name
- Valproic Acid, Free and Total
- Lab Code
- RFTVPA
- Epic Name
- Valproic Acid, Free and Total (Sendout)
- External Test Id
- VALPG
- Description
Useful For:
- Monitoring both total and free valproic acid levels in therapy
- Assessing compliance
- Evaluating potential toxicity
Ordering Guidance: Order this test to obtain free and total valproic acid levels. For total valproic acid only, refer to Valproic Acid (Depakene) [VPA].
- References
- Mayo Clinical & Interpretive Information: Valproic Acid, Free and Total, Serum
- Synonyms
- Depakene, Depakote, Divalproex, Free Valproic Acid, VALPG, Valproate
- Components
-
Code Name RFVPA Valproic Acid, Free RTVPA Valproic Acid, Total
Interpretation
- Method
Valproic Acid, Total: Immunoassay Valproic Acid; Valproic Acid, Free: Ultrafiltration Followed by Immunoassay
- Reference Range
- See individual components
- Ref. Range Notes
Reference Values:
Valproic Acid, Total:
Therapeutic: 50 (trough)-125 (peak) mcg/mL Critical value: > or =151 mcg/mL Valproic Acid, Free:
Therapeutic: 5-25 mcg/mL Critical value: >30 mcg/mL Interpretation:
The generally acceptable range for total valproic acid used as a reference to guide therapy is 50 to 125 mcg/mL. The corresponding range of free valproic acid concentration for clinical reference is 5 to 25 mcg/mL.
Low free valproic acid concentration relative to these ranges may suggest inadequate dosing, whereas a high free valproic acid concentration may be associated with toxic effects.
Because the concentration of valproic acid fluctuates considerably depending on the time from last dose, interpretation of the clinical significance of the valproic acid concentration must take into consideration the timing of the blood specimen. For this reason, 2 collections are sometimes made to assess the trough and peak concentrations.
- Interferences and Limitations
Cautions: Specimens subjected to significant heat or other factors that could cause protein denaturation would demonstrate an artificially increased free valproic acid.
- References
- Mayo Clinical & Interpretive Information: Valproic Acid, Free and Total, Serum
Ordering & Collection
- Specimen Type
- Blood
- Collection
-
6 mL blood in GOLD TOP SST or RED TOP tube
- Handling Instructions
Outside Laboratories: Centrifuge sample and aliquot serum into a separate plastic vial within 2 hours of collection. Refrigerate serum while awaiting shipment. Transport with a cold pack.
Stability: Refrigerated (preferred): 14 days; Frozen: 28 days; Ambient: 72 hours.
Reject Due To: Gross hemolysis.
- Quantity
-
Requested: 2 mL serum
Minimum: 1 mL serum
Processing
- Receiving Instructions
Centrifuge sample and aliquot serum into a separate plastic vial within 2 hours of collection. Refrigerate serum.
Sendouts:
- Order Mayo Test: VALPG
- Interfaced: Yes [Interface: 601; Worksheet: MARF]
Stability: Refrigerated (preferred): 14 days; Frozen: 28 days; Ambient: 72 hours.
Reject Due To: Gross hemolysis.
- Misc Sendout
Performance
- Lab Department
- Sendouts Mayo Lab (RF)(MARF)
- Frequency
- Performed: Monday through Sunday. Reported: 1 day from sample receipt at Mayo Clinic Labs.
- Available STAT?
- No
- Performing Location(s)
-
Sendout Mayo Clinic Laboratories
800-533-1710200 First Street Southwest
Rochester, MN 55901
Billing & Coding
- CPT Codes
- 80164, 80165
- LOINC
- 4086-5
- Interfaced Order Code
- UOW5024