Randomized, single-dose, two-period, two-sequence crossover bioequivalence study evaluating two oral formulations of lamotrigine in healthy volunteers

Background: Lamotrigine is an anti-epileptic medicine used to treat epilepsy and bipolar disorder. The mechanism of action is to block voltage activated sodium channels. The aim of this study was to evaluate the bioequivalence of 2 oral formulations of lamotrigine 25 mg in healthy volunteers.Methods: A single-dose, two-period, randomized crossover study design in - healthy Indian adult volunteers was conducted at Amaris Clinical, a division of Caplin Point Laboratories Ltd., Chennai. A validated high performance liquid chromatography in conjunction with mass spectrometry was used. Lamotrigine concentration in plasma. Adverse events were determined by measuring vital functions after dosing. A total of 24 subjects were included.Results: The mean and 90% confidence intervals of the test / reference ratios for these parameters were as follows: The mean Cmax and Tmax of the test were 758.606 (157.453) ng / ml and 1.17 (0.50-5.00) hours, respectively. The mean Cmax and Tmax of the reference were 775.993 (151.654) ng / ml or 0.88 (0.25-4.00) hours. The mean AUC0-72 was 24142. 031±3641.691 (ng.hr/mL) for the test formulation and 24202.099±3742.957 (ng. h / ml) for the reference formulation. The mean test / reference ratios for Cmax and AUC0-72 were 97.92 and 99.82 respectively. The 90% parametric CIs for Cmax and AUC0-72 were 90.17-105.68% or 97.87-101.81%.Conclusions: The 90% confidence intervals ranged from 80-125% and it was concluded that the test product was bioequivalent to the reference product in these healthy adult male volunteers.

Lamotrigine ODT-Induced Seizure in a 3-Year-Old Child after Accidental Ingestion

Lamotrigine is a new generation antiepileptic which blocks sodium channels and can cause significant toxicity in overdose. A case of a three-year-old child who suffered a seizure and required endotracheal intubation after accidental lamotrigine ingestion is presented. The lamotrigine concentration measured 23.2 mcg/mL which is the highest reported after accidental pediatric exposure. A review of the literature regarding pediatric lamotrigine poisoning is also included.