Are generic drugs really the same as branded drugs?

Consumers are told that generics are just like their name-brand counterparts. More medical professionals are starting to say that’s not the case. http://www.ebiochem.com

In October the Food and Drug Administration took a highly unusual step: It declared that a generic drug it had previously approved — a version of the popular antidepressant Wellbutrin — was not in fact “bioequivalent” to the name-brand version. The FDA withdrew its approval. http://www.ebiochem.com

The federal action shook the business. Teva Pharmaceuticals (TEVA), which marketed the generic in question, has stopped selling it, and other companies are now testing their versions of Wellbutrin at the FDA’s request. The episode is bringing momentum to a movement that has been quietly building among many doctors and medical societies that are increasingly willing to ask a question that borders on heresy: Are generics really identical to the branded products they are meant to replicate? To a surprising degree, they say, the answer is no.This FDA action injected new power to develop generics. http://www.ebiochem.com

If you’re a layperson, this is the way you probably think of generics: They’re the exact same products in different packaging; generics companies can sell such medications for a fraction of the cost of the originals because they don’t have to spend huge sums on drug development and marketing. http://www.ebiochem.com

That apparent miracle explains why more than 80% of all U.S. prescriptions dispensed in 2012 were generic. Using nonbranded medications saved Americans $193 billion this past year, according to the Generic Pharmaceutical Association. http://www.ebiochem.com

But generic drugs diverge from the originals far more than most of us believe. For starters, it’s not as if the maker of the original pharmaceutical hands over its manufacturing blueprint when its patent runs out or is challenged. The patent reveals the components, but it doesn’t explain how to make the drug. In reality, manufacturing a generic requires reverse engineering, and the result is an approximation rather than a duplicate of the original. http://www.ebiochem.com

The FDA’s rules effectively acknowledge that. The agency’s definition of bioequivalence is surprisingly broad: A generic’s maximum concentration of active ingredient in the blood must not fall more than 20% below or 25% above that of the brand name. This means a potential range of 45%, by that measure, among generics labeled as being the same. http://www.ebiochem.com

There are other differences. The generic must contain the same active ingredient as the original. But the additional ingredients, known as excipients, can be different and are often of lower quality. Those differences can affect what’s called bioavailability — the amount of drug that could potentially be absorbed into the bloodstream. As the American Heart Association recently noted, “Some additives traditionally thought to be inert, such as alcohol sugars, cyclodextrans, and polysorbate-80, may alter a drug’s dissolution, thereby impacting its bioavailability.” http://www.ebiochem.com

 

Author:Katherine Eban