Lamotrigine (LAMICTAL, 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine) is an anti-convulsant drug approved for use in the treatment of epilepsy and is often prescribed as monotherapy or as one component of a multiple anti-epileptic drug therapy. Although the mechanism of action for lamotrigine is not entirely understood, research has shown that lamotrigine selectively binds and inhibits voltage-gated sodium channels, stabilizing presynaptic neuronal membranes and inhibit presynaptic glutamate and aspartate release. Lamotrigene is 55% bound to plasma proteins and metabolized predominantly to an inactive 2-N-gluoronide conjugate. The peak plasma concentration occurs at 1.4 to 4.8 hours following oral administration. The elimination half-life varies from 12-70 hours. The most common adverse reactions are associated with the use of lamotrigine in combination with other anticonvulsants, and include dizziness, chest pain, back pain, edema, diplopia, ataxia, blurred vision, nausea and vomiting, somnolence, headache, and rash.
Solaris Diagnostics Laboratory Lamotrigene assay is for in vitro diagnostics use in quantitative measurement of Lamotrigene assay in human serum and plasma with turnaround time of less than 24 hours from the time specimen is received in the laboratory. Lamotrigene assay is a homogeneous immunoassay based on competition between drug in the specimen and lamotrigine labeled with the enzyme glucose-6 phosphate dehydrogenase (G6PDH) for binding to the antibody reagent. As the latter bind’s antibody, enzyme activity decreases. In the presence of drug from the specimen, enzyme activity increases and is directly proportional to the drug concentration. Active enzyme converts the coenzyme nicotinamide adenine dinucleotide (NAD) to NADH that is measured spectrophotometrically as a rate of change in absorbance.