Quality control concerns in relation to lamotrigine and their impact

To pursue explanations for compromised efficacy and induction of side-effects in some generic brands of lamotrigine distributed in Australia.

Bioassays of the non-generic and five generic lamotrigine tablets were undertaken (also after exposure to heat and cold), as well as assays of two generic drugs generating concerning side-effects in two patients, while enquiries were made of manufacturing companies.

Mass spectrometry of the six tested products showed comparable properties and no compromising when those tablets were heated and cooled, while analyses of the products taken by the two patients reporting significant side-effects showed an increase in the peak area lamotrigine concentration.

We failed to identify any intrinsically compromised product in our comparison analyses of the six preparations. We consider alternate explanations for an issue leading to widespread international reporting of distinct side-effects and deaths following brand switching, with analyses of the two problematic preparations supporting a 'faulty' batch explanation.