Topiramate

Test Code

TOP

Quest Code

30965

CPT Codes
80201

Preferred Specimen

1 mL serum collected in a red-top tube (no gel), or no additive (royal blue-top) tube, or plasma collected in a lithium heparin (green-top) tube

Minimum Volume

0.5 mL

Other Acceptable Specimens

Plasma collected in a sodium heparin (green-top), or sodium heparin lead-free (tan-top) tube

Instructions

Draw at peak (2-4 hours after dose) or trough (0.5-1 hour before dose) at steady-state.

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 14 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gel barrier/serum separator tube

Methodology
Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Mon-Sat a.m.; Report available: 2 days

Reference Range

Therapeutic Range

Dose (mg)	Peak (mcg/mL)	Trough (mcg/mL)
100	6.5-9.2	4.5-6.6
200	12.0-16.0	8.0-12.0
400	20.0-30.0	14.0-20.0

Clinical Significance

Topiramate is an anticonvulsant used as an adjunctive treatment of partial-onset epilepsy. Therapeutic drug monitoring is useful to optimize dose and avoid toxicity.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

Last Updated: July 6, 2018

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.