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HelpTest Code LAB498 Topiramate, Serum
Additional Codes
TOPI
Useful For
Monitoring serum concentrations of topiramate
Assessing compliance
Assessing potential toxicity
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL serum
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
On-campus collections: Tube to 99 or deliver to University Extension Hospital Room EH318. Submission Container/Tube: Plastic vial, Refrigerated
Off-campus collections: Centrifuge and aliquot within 2 hours. Specimen to be stored/transported Refrigerated.
Specimen Minimum Volume
Serum: 0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 28 days |
| Ambient | 28 days | |
| Frozen | 28 days |
Reference Values
Anticonvulsant: 5.0-20.0 mcg/mL
Day(s) Performed
Monday through Friday
CPT Code Information
80201
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TOPI | Topiramate, S | 17713-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 81546 | Topiramate, S | 17713-9 |
Interpretation
Most individuals display optimal response to topiramate with serum levels 5.0 to 20.0 mcg/mL when used to control seizures. Some individuals may respond well outside of this range or may display toxicity within the therapeutic range; thus, interpretation should include clinical evaluation.
Therapeutic ranges are based on specimens collected at trough (ie, immediately before the next dose).
Toxic levels have not been well established.
Method Description
The serum sample is crashed with acetonitrile containing the deuterium labeled internal standard. The protein precipitate is centrifuged and a portion of the supernatant is diluted with Mobile Phase 1 for detection by tandem mass spectrometry (MS/MS).(Unpublished Mayo method)
Report Available
1 to 2 daysSpecimen Retention Time
14 daysReject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Secondary ID
81546Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Neurology Specialty Testing Client Test Request (T732)
-Therapeutics Test Request (T831)