NIH Clinical Center
Dept. of Lab Medicine | Dept. of Transfusion Medicine | Anatomic Pathology Test Guide > Lab Test
 Lab Test
 Test Description
Panel Name:
Test Name:
Panel Tests:
LIS Test Code:LAMO2
Synonyms: Lamictal
Department:Laboratory Medicine
Lab Area:Mayo Medical Labs
TAT:1-3 days
 Specimen Collection


Container:Red (Plastic)

Micro. Container:

Collection Instructions:

Delivery Instructions:Send specimen to 2C324 or Tube Station 321
Specimen Type: Blood
Frequency / Restrictions:
 Expected Values/Results

Ranges and Interpretation:

Lamotrigine  mcg/mL  (SI: mg/L = 1.0 x  mcg/mL)
Performed at Mayo Medical Labs, Rochester MN
Effective 31Mar09 – present:
Trough    2.5 – 15.0  
While most patients show response to the drug when the trough concentration is in the range of 2.5 mcg/mL to 15.0 mcg/mL, and show signs of toxicity when the peak serum concentration is >20 mcg/mL, some patients can tolerate peak concentrations as high as 70 mcg/mL.

Organisms Reported:

Alert Limits:

 Additional Test Information


Lamotrigine (Lamictal) is approved for therapy of bipolar I disorder and a wide variety of seizure disorders including Lennox-Gastaut syndrome, primary generalized tonic-clonic seizures, and partial seizures. Its many off-label uses include treatment of migraine, trigeminal neuralgia, and treatment-refractory depression. Lamotrigine inhibits glutamate release (an excitatory amino acid) and voltage-sensitive sodium channels to stabilize neuronal membranes; it also weakly inhibits the 5-HT3 (serotonin) receptor.

Lamotrigine oral bioavailability is very high (approximately 98%).The drug is metabolized by glucuronic acid conjugation to inactive metabolites. The half-life is 25 to 33 hours in adults, but decreases with concurrent use of phenytoin or carbamazepine (13-14 hours), and increases with concomitant valproic acid therapy (59-70 hours), renal dysfunction, or hepatic impairment. The therapeutic range is relatively wide, 2.5 mcg/mL to 15 mcg/mL for most individuals. Common adverse effects are dizziness, ataxia, blurred or double vision, nausea, or vomiting.


High Turbulence Liquid Chromatography - Tandem Mass Spectrometry (HTLC-MS/MS)


Archived Ranges:Historical Reference Ranges


NIH Clinical Center | Credits | Admnistrative Login

For technical support, contact DCRI Application Support or
the developer: Richard Farina,


N I H logo - link to the National Institutes of Health      H H S logo - link to U. S. Department of Health and Human Services