Test Code ZG094 Valproic Acid, Free and Total, Serum
Additional Codes
MAYO:VALPG
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, SSpecimen Type
SerumSpecimen Required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
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 aliquoted 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 |
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
Day(s) and Time(s) Performed
Monday through Sunday; Continuously
Performing Laboratory

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 |