Test Name
Valproic Acid (Depakote)
Specimen Type & Acceptability
Serum
7 days refrigerated.
General Use
Therapeutic drug monitoring of patients taking Valproic Acid.
CPT Code(s)
80164
Special Instructions
Let clot for 10-20 minutes. After the sample is fully clotted, centrifuge the sample. Verify complete separation of cells and serum and refrigerate. Ensure the sample is labeled with a minimum of 2 unique patient identifiers and refrigerate. Please provide all dosing information, i.e. last dose and time.
Valproic Therapeutic peak level:
Reference Range for Therapeutic Concentration = 50.0 – 100.0 μg/mL
Time to peak oral dose for serum:
Divalproex sodium:
- Delayed release (DR): tablet and sprinkle capsules: ~4 hours
- Extended-release (ER), 24-hour: 4 to 17 hours
- Immediate release enteric-coated tablet [Canadian product]: 4 hours
Valproic acid:
- Delayed release capsule: 2 hours
Container/Tube Type
Volume
0.5 mL Min. vol. = 100 ul
Suggested Tube Types
Description
Typical Volume
Gold Top Serum Separator Tube (SST)
⋜ 5 mL
Tiger Top Serum Separator Tube (SST)
^For larger volume tests
> 5 mL
Red Top Tube (No additive)
⋜ 5 mL
EDTA Whole Blood
3 mL
3.2 % Sodium Citrate Whole Blood
2.7 mL
Lithium Heparin Plasma Separator Tube
⋜ 5 mL