Antrim #31435, EPIC: LAB5426, SOFT: TOPIR
Specimen Collection Criteria
Collect: One plain Red-top tube. (Minimum Whole Blood: 2.0 mL)
Do not use Serum Separator Tubes.
Time of Collection: Trough, just prior to the next dose.
Record the exact time of specimen collection on the tube or in the computer system.
Physician Office/Draw Specimen Preparation
Let specimens clot 30-60 minutes. Refrigerate (2-8°C or 36-46°F) the collection tube within two hours of collection. (Minimum: 2.0 mL blood)
Preparation for Courier Transport
Transport: Collection tube, refrigerated (2-8°C or 36-46°F). (Minimum: 2.0 mL blood)
- Serum Separator (SST) tubes.
- Severely lipemic or hemolyzed specimens.
Let specimens clot 30-60 minutes. Centrifuge specimen to separate serum from cells. Deliver an aliquot of serum or the collection tube immediately to the appropriate testing station.
Specimen Stability for Testing:
Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months
Specimen Storage in Department Prior to Disposal:
Frozen (-20°C/-4°F or below): 1 months
Royal Oak Toxicology Laboratory
Sunday – Saturday.
Results available the same day as testing performed.
Therapeutic Range: 5-25 mcg/mL.
Critical Value: 40 mcg/mL.
Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS).
This test was developed and its performance characteristics determined by Beaumont Health. It has not been cleared or approved by the FDA. The Laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes and should not be regarded as investigational or for research.
Topiramate is distributed extensively to red blood cells. Hemolysis will falsely elevate serum measurements. The Topiramate elimination half-life is about 24 hours with a time to steady-state of 4 days for the average patient. Topiramate is eliminated by renal and metabolic means. A decline in renal function will increase Topiramate steady-state concentrations and hemodialysis will decrease concentrations requiring supplemental dosing. Concurrent drugs that induce hepatic metabolism [Phenytoin, Carbamazepine] may decrease steady-state Topiramate concentrations. Co-administration with Lamotrigine may increase Topiramate concentrations by 15%.
Topiramate is approved as monotherapy in patients 10 years of age or older with partial onset or primary generalized tonic-clonic seizures. It is also approved as adjunct therapy in the treatment of partial onset seizures or primary generalized tonic-clonic seizures in adults and children between the ages of 2 to 16 years. It is approved for treatment of patients 2 years of age or older for Lennox-Gastaut syndrome. It is approved for the prophylactic management of migraine in adults.
Toxicology Laboratory – RO
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