Skip to Content
UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Lamotrigine

Test Code(s): LAMO / XLAMO

CPT Code(s): 80175

Methodology: Liquid Chromatography

Clinical Significance: Anticonvulsant

Days Performed: Daily, dayshift.

Turnaround Time: Routine: 24 hours.

Specimen Requirements

Specimen: Blood

Collection Instructions: Collect specimen for trough level prior to next dose.

Collection Container: Preferred: Red top

Collection Volume: Preferred: 3 mL
Pediatrics: 1 mL

Sample Analyzed: Serum

Volume Required: Preferred: 1 mL

Specimen Processing: Centrifuge. Transfer serum to clean tube. Refrigerate.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.

Unacceptable Criteria: Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.

Stability: Ambient: 6 days
Refrigerated: 7 days
Frozen: 14 days


Interpretive Guidelines:

Therapeutic concentrations of lamotrigine have not been established. Dosing should be guided by clinical response. In general, a trough concentration of 2.0-15.0 mcg/mL is considered effective for individuals 18 years old and up.

Critical Calls: View

Additional Information:

A result of "BELOW" indicates that the result is below the method detection limit of 0.5 mcg/mL. A pharmacodynamic interaction may occur with carbamazepine, phenytoin, or phenobarbital, lowering blood levels of lamotrigine. Valproic acid slows lamotrigine metabolism, thus raising blood levels.


This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories.  This test meets the standards for clinical testing.  This test should not be regarded as investigational or for research use.  The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.


Back to Lab Test Directory Index