Important bioequivalence issues regarding anti-epileptic drugs were highlighted at the FDA Town Hall meeting held during AES 2015.
The generic versus brand-name drug debate has long been a hot-button issue in the epilepsy community. But the findings of research presented at the American Epilepsy Society’s Annual Meeting revealed that brand-name and generic formulations of anti-epileptic drugs (AED) are, for all intents and purposes, the same.
During a special Food and Drug Administration (FDA) Town Hall Update, speakers explained that neurologists, patients, and patient advocacy groups have been skeptical whether product bioequivalence established in healthy individuals can ensure the same result in AEDs used by people with epilepsy.
What is the reason for such doubt? The FDA determines bioequivalency of generic drugs based on single-dose studies in normal, healthy individuals. And until recently, a majority of uncontrolled studies have suggested lack of efficacy or increased adverse events when people with epilepsy switched from brand to generic AEDs
To address the epilepsy community’s concern, the FDA Office of Generic Drugs funded a series of brand-to-generic AED switching studies in epilepsy patients, including the Bioequivalence in Epilepsy Patients (BEEP) and Equivalence in Generic Drugs (EQUIGEN) studies.
In both US studies, lamotrigine was used as the study drug because of its pharmacokinetic parameters and accessible study population. The overall results from both studies indicated that the generic versions of lamotrigine are pharmacokinetically equivalent to the original drug.
Speakers addressed reasons why problems are occasionally reported among generic drug users, citing issues such as variation in color and appearance of the brand and generic drugs as well as the “nocebo” effect, when patients experience negative effects based on expectations and other psychological factors. One expert said that, for some patients, the mere suggestion of a drug’s side effects is enough to trigger negative symptoms, such as erectile dysfunction.
Michael Privitera, MD, Director of the Epilepsy Center at University of Cincinnati Epilepsy Center, said this new and promising data provide reassurance to both the prescribers of generic drugs and the users. More particularly, the findings arm health care providers with concrete facts to debunk the myths surrounding the use of generic drugs.
According to the FDA, approximately 80% of all prescriptions filled in the United States are for generic drugs. In 2010 alone, the use of FDA-approved generics saved $158 billion-an average of $3 billion every week.
In most states, unless a physician explicitly writes “dispense as written” or “no substitution,” pharmacists can switch a patient to a lower-cost generic drug without the consent or knowledge of either the patient or the physician.
The AES 2015 Annual Meeting was held December 4-8 in Philadelphia.
Session: FDA Town Hall Update: Generic Antiepileptic Drug Bioequivalence in Epilepsy Patients: From Anecdotes to Evidence. Dec. 7, 2015.