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HelpTest Code LAB4220 VALPROIC ACID
Specimen Type
Preferred Sample: Lithium Heparin Plasma (Mint Green Top, Dark Green Top)
Alternative Sample: Serum (SST, Gold, Corvac, Tiger, Red Top Tube)
* See Test Limitations on this page for information about tubes containing gel.
Specimen Volume
1 mL
Minimum Volume
0.5 mL
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Method
Colorimetric
Reference Ranges
Valproic Acid µg/mL (Peak or Trough)
Therapeutic 50-100
Toxic: Greater Than 150
Synonyms
Depakene; Depakote; Divalproex
CPT Codes
80164
Test Components
Valproic Acid, µg/mL.
Collection Instructions
Draw just prior to next dose. Note times of dose and drawing.
Test Limitations
Studies have shown that therapeutic drug levels may be altered in serum/plasma that remains in contact with separator gel. Therapeutic drug levels collected in gel tubes (SST or PST) should be run within 4 hrs of collection. If a physician requests, the test will be performed after the recommended 4 hr stability period but a disclaimer will be attached to the result.
Clinical Information
Valproic acid (2-propylpentanoic acid; Depakene) is a broad spectrum anticonvulsant drug used solely or in combination with other anticonvulsant drugs for the treatment of absence seizures. It also has demonstrated effectiveness in the management of generalized tonic-clonic and myoclonic seizures, as well as atypical absence, simple and complex partial, and mixed grand mal and petit mal seizures. The capability of treating many types of seizures with a single anticonvulsant has resulted in the widespread use of valproic acid, particularly in children in whom tonic-clonic and myoclonic seizures are most prevalent. Valproic acid has proven effective in the treatment of many patients otherwise refractory to other anticonvulsant treatments. Most patients receiving valproic acid do not develop a tolerance to its anticonvulsant effects.
To confirm that an adequate dose has been prescribed, specimens for the Alinity c Valproic Acid assay should be drawn at trough levels, just prior to a dose. The trough concentration is most indicative of the therapeutic value of valproic acid.