| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
VALPROIC ACID LEVEL
Test CodeLAB24
CPT Codes
80164
Preferred Specimen
One 6 mL red top tube
Pediatric: One red top microtainer
Pediatric: One red top microtainer
Other Acceptable Specimens
One dark green top tube
Instructions
Specify dosage history. Time drawn must be written on label.
Sample must be centrifuged within two hours of collection. Serum/plasma (red or dark green top tube) must be removed from the red cells and put into aliquot tubes following centrifugation.
Sample must be centrifuged within two hours of collection. Serum/plasma (red or dark green top tube) must be removed from the red cells and put into aliquot tubes following centrifugation.
Transport Temperature
Refrigerated
Specimen Stability
Unstable, centrifuge within two hours of collection, must be seperated from cells within two hours of collection
Ambient: 24 hours
Refrigerated: 48 hours
Frozen: 7 days
Ambient: 24 hours
Refrigerated: 48 hours
Frozen: 7 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Samples drawn in a tube with a separator gel will be rejected. The separator gel may cause falsely lower results.
Methodology
Immunoturbidimetric
Setup Schedule
Sunday-Saturday
Reference Range
Therapeutic: 50.0-100.0 µg/mL
Toxic (Critical value): >=101.0 ug/mL
Toxic (Critical value): >=101.0 ug/mL
Clinical Significance
Valproic acid therapy requires ~2-3 days to reach steady-state (half-life ~ 6-16 hours).
Trough levels are drawn immediately prior to the next scheduled dose. Trough levels are initially drawn 2-4 days after initiating therapy.
Peak levels may be determined 2-3 hours after an intravenous or orally administered loading dose to aid in determining a maintenance dose or a need to reload.
Consider monitoring blood cell counts, liver function tests, ammonia.
Valproic acid can inhibit cytochrom P-450 activity.
Trough levels are drawn immediately prior to the next scheduled dose. Trough levels are initially drawn 2-4 days after initiating therapy.
Peak levels may be determined 2-3 hours after an intravenous or orally administered loading dose to aid in determining a maintenance dose or a need to reload.
Consider monitoring blood cell counts, liver function tests, ammonia.
Valproic acid can inhibit cytochrom P-450 activity.
Performing Laboratory
West Virginia University Hospital, Inc.
Berkeley Medical Center Camden Clark Medical Center Garrett Regional Medical Center Jefferson Medical Center Princeton Community Hospital Potomac Valley Hospital Reynolds Memorial Hospital Summersville Regional Medical Center St. Joseph’s Hospital United Hospital Center Uniontown Hospital Wetzel County Hospital Wheeling Hospital
