“Generic” does not equal “identical.” That’s why the FDA wants to tighten certain bioequivalence standards.
Generic-drug makers will have to meet tighter standards to prove that “critical dose drugs” such as blood- thinners and anti-seizure treatments, work as well brand-name products. And it’s about time.
The FDA, responding to complaints that some copies don’t work as well as the originals, is writing guidelines for limits companies must follow that include how fast active ingredients are absorbed in the bloodstream.
Critical dose drugs have a narrow therapeutic index, meaning that small changes in blood concentration have the potential to result in serious therapeutic failures and/or serious adverse drug reactions.
The FDA is outlining its plans to companies after patients and employees of generic-drug makers complained to regulators that some of the medicines don’t work as well as the originals.
And, according to Lawrence Yu, deputy director for science and chemistry in the agency’s Office of Generic Drugs, “Ideally, they should start using them now.”
Currently, the "sameness" of a brand product and a generic version is evaluated based on two-treatment crossover study to prove bioequivalence, the aim being to show that the 90 percent confidence intervals of the geometric mean test/reference ratios for both maximum plasma concentration and the area under the plasma concentration-time curve fall within a range of 80 percent to 125 percent. The agency is now requiring a rate between 90 percent and 111 percent for narrow therapeutic index drugs.
A generic drug’s potency will also have to fall within 95 percent and 105 percent of the original. Currently, drugs can fall within a range of 90 percent to 110 percent.
The FDA plans to release guidelines on the stricter standards, Yu said, declining to say when. Well, the sooner the better -- because a confused public wants to know.
A Consumer Reports poll of 1,226 adults in June showed 39 percent of respondents had concerns or misconceptions about generics while 21 percent thought the copies weren’t as effective as brand-name products. Twenty-one percent didn’t trust generics as much as brand-name drugs and 14 percent said they didn’t think the products were as safe.
Pharmacists “hope that FDA tightening the standards does in fact help alleviate some consumer skepticism about generics,” said Chrissy Kopple, a spokeswoman for the National Association of Chain Drug Stores.