Generic Epilepsy Drug Shows Equal Efficacy

Different generic lamotrigine products work equally well for epilepsy according to a recent trial conducted in Cincinnati, Ohio.

The research team was led by Michael D. Privitera, MD, of the University of Cincinnati Medical Center, and colleagues, and was published in The Lancet Neurology on February 11, 2016.

“Patients and clinicians share concerns that generic drug substitution might lead to loss of efficacy or emergence of adverse events,” say the researchers.

They add that the aim of this study was to assess “US Food and Drug Administration (FDA) bioequivalence standards by studying the effects of switching between two disparate generic immediate-release lamotrigine products in patients with epilepsy.”

The title of the study is" Equivalence among Generic Antiepileptic Drugs (EQUIGEN)", and it was designed as a randomized, double-blind, crossover study. Participants were recruited from six different epilepsy centers in the United States, patients who were already taking immediate-release lamotrigine at 100 mg, 200 mg, 300 mg, or 400 mg doses twice per day.

A total of 33 patients completed the entire study, and were enrolled in the study between April 25, 2013 and August 12, 2014. There were four treatment periods, divided into 2 sequences.

Each treatment period lasted 14 days and “patients received balanced doses of an oral generic lamotrigine product every 12 hours,” according to the researchers. At the end of the 14-day treatment period, the patients were switched to a different generic product. In order to decrease the likelihood of bias, “Both patients and study personnel were masked to the generic products selected, their predicted exposure, and their group allocation,” the researchers reported.

The researchers concluded, “Disparate generic lamotrigine products in patients with epilepsy showed bioequivalence with no detectable difference in clinical effects, confirming that US Food and Drug Administration bioequivalence standards are appropriate."