Test Name

Valproic Acid (Depakote)

Specimen Type & Acceptability

7 days refrigerated.

General Use

Therapeutic drug monitoring of patients taking Valproic Acid.

CPT Code(s)


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


0.5 mL Min. vol. = 100 ul

Suggested Tube Types


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