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HelpTest Code TOPI Topiramate, Serum
Additional Codes
Alias:
Topamax
Reporting Name
Topiramate, SUseful For
Monitoring serum concentrations of topiramate
Assessing compliance
Assessing potential toxicity
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedSpecimen Required
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Centrifuge and aliquot serum into plastic vial; within 2 hours of collection.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| 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
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.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.
Clinical Reference
1. Patsalos PN, Berry DJ, Bourgeois BF, et al. Antiepileptic drugs-best practice guidelines for therapeutic drug monitoring: a position paper by the subcommission on therapeutic drug monitoring, ILAE Commission on Therapeutic Strategies. Epilepsia. 2008;49(7):1239-1276
2.. Johannessen SI, Tomsom T. Pharmacokinetic variability of newer antiepileptic drugs: when is monitoring needed? Clin Pharmacokinet. 2006;45(11):1061-1075
3. Milone MC, Shaw LM. Therapeutic drugs and their management. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:420-453
4. Patsalos PN, Spencer EP, Berry DJ. Therapeutic Drug Monitoring of Antiepileptic Drugs in Epilepsy: a 2018 Update. Ther Drug Monit. 2018;40(5):526-548
5. Hiemke C, Bergemann N, Clement HW, et al. Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017. Pharmacopsychiatry 2018;51(1-02):9-62
Report Available
1 to 2 daysForms
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)