Clinical Use: Recommended sampling time -trough levels (consistently)
Background: Valproate is used in the control of grand and petit mal epilepsy and as such requires therapeutic drug monitoring. The drug is completely absorbed reaching a peak in approximately 4 hours with 90% being protein bound. It affects and is affected by concomitant use of phenytoin. Although the mechanism is not fully understood it appears to increase gamma-aminobutyric acid (GABA) levels which have anticonvulsant properties.
Reference Ranges: Therapeutic Range: 50 – 100 mg/L
Associated Diseases:
Patient Preparation:
Specimen Requirements: Sample type:

  • Serum and Plasma (Lithium Heparin)

Sample identification:

  • Three patient identifiers from
    • Name
    • D.O.B.
    • Address
    • N.H.S. number
    • Unit Number

    should match on the specimen and request form. This check may be performed prior to centrifugation by the Central Sort department.

Turnaround Time: 2 hours
Additional Information:
Referred Test:
Location: