Detection And Clinical Analysis Of Lamotrigine Plasma Concentration In Epilepsy Patients

Objective The purpose of this study was to establish a detection oflamotrigine plasma concentration, to investigate the relationship betweenplasma concentration and dose and efficacy of lamotrigine by the result ofdetection.Methods A high-performance liquid chromatographic (HPLC) methodfor the determination of lamotrigine in plasma is described and validated.The drug was extracted from100ml of plasma with chloroform. Thedrug and the internal standard (tinidazole) were eluted from a SymmetryC18stainless steel column at ambient temperature with a mobile phaseconsisting of acetonitrile-0.02M potassium phosphate(25:75v:v), at aflow rate of1.0ml min-1and the detector was monitored at210nm.Thecases were divided into three groups: low concentration group(<1μg/mL,n=4),the effective concentration group(1~8μ g/mL,n=49) and highconcentration group(>8μ g/mL,n=7) according to the results oflamotrigine concentration detected by the validated high performanceliquid chromatographic(HPLC).Then the results were analyzed bystatistical software SPSS16.0.Results The linear range of lamotrigine was1～8μ g/mL（r＝0.9998）.The lowest detection concentration was0.5μ g/mL. The extractionrecovery was66.6％～70.0％.The RSD of intra-day and inter-day wereboth below6.93％. The result of HPLC analysis showed that: There were49cases of Epilepsy whose lamotrigine concentration were between therange of1~8μ g/mL,43cases taken the dosage of50mg~200mg. LTG have a significant efficacy in the treatment of various types of epilepsy,particularly on the generalized seizures. The effcient of LTG have asignificant difference between partial seizures and generalized seizures(P<0.05) when the concentration between the range of1~8μ g/mL.Conclusions The method provides a simple、 high sensitivity andeconomical way for monitoring plasma level of lamotrigine, it would bevaluable in monitoring plasma level and investigation of thepharmacokinetics of Lamotrigine. LTG have a significant efficacy in thetreatment of various types of epilepsy, when administered in a dose rangeof50mg~200mg, most patients,plasma concentrations can achievetherapeutically effective concentration of1~8μ g/mL. Within this range,generalized seizures could achieve better efficacy.