Tuesday, April 27, 2010

How Good Are Generic Drugs?

Thanks to Merrill Goozner for his report and insights:

First, some of my own background: There are several issues that concern us on this blog that all in some way implicate the safety and efficacy of generic drugs as equivalent to brand-name drugs. Specifically, if it were to turn out that we could not rely on generics as reasonably equivalent to the brand-name in a therapeutic sense, then a number of the pieces of advice that we'd like to give to the physician, on how to save money for patients, how to keep well informed about drugs, etc. would no longer be valid and we'd have to start over from scratch. That is why it was a truly big deal when, back in 1989, a Congressional inquiry revealed a payola scandal within the FDA's generics division that allowed non-equivalent drugs to slip through the net (as I briefly described in HOOKED). What I have written since then all assumes that the problem at the FDA was fixed. The issue is especially timely today as many widely-prescribed brand-name drugs either have just gone generic in the past couple of years or are poised soon to do so.

Now, over to Gooz--his article briefly reviews recent charges, taken up by some popular magazines and by psychiatrists in particular, about patients who switched to a generic drug and had an immediate worsening of their symptoms. This led the FDA to convene an advisory committee to review the standards it uses for determining bioequivalence. The short answer is that the FDA internal investigation showed that even if they had adopted a stricter standard, the specific drugs that have recently been questioned all fell within those tighter limits--so there was no scientific reason to change the standards.

Gooz's analysis is extremely helpful because he distinguishes two FDA functions--generic drug approval and on-site inspection of drug manufacturing facilities. Megabrand Generic Drugs Inc. might submit their formulation for a generic version of (say) Zoloft to the FDA. There is, at present, no evidence at all that there's anything wrong with the process the FDA uses to approve that chemical formulation. But then somebody actually has to run a big machine in a big factory and make millions of those generic pills or capsules. And that is where the available evidence would suggest that things could get dicey--especially if the factory is in China or some other country prone to either official corruption or sloppy standards or both. The FDA, it is now widely admitted, has way too few inspectors to keep an eye on all the outsourced drug factories that supply their wares to the US market, as we found out with tainted Chinese heparin recently. So we should fix that and not worry about the official generic approval standards.

Now, my own advice as a no-longer-practicing family doc. What should the physician do when the patient says that after switching over to a generic brand, he has a new side effect, or the drug stopped working? As I understand the matter, two different brands of the drug may be chemically different, having, for instance, a different type of chemical filler. So I have no trouble believing that no matter what FDA standard the generic drug passed, this individual patient just might have a chemical idiosyncrasy so that his body absorbs some substances differently, etc. (Or he might not--the difference truly might be imaginary, or a negative placebo effect--but the research needed to find out for sure is way beyond the time and abilities of most practitioners.) In such cases I always wrote the prescription so as to return to the brand name drug. I never told the patient I did not believe him, or that what he said could not be true because generic drugs are equivalent. And if the insurer did not want to pay the higher price, I always went to bat for the patient (and made sure the reported difference was documented in my chart note to back up the patient's story). But at the same time, I felt obliged to tell the patient not to assume that this meant that other generic drugs were no good. I explained that the same thing could have happened, had he initially been on a generic drug and had been switched to the brand name version. The problem in his case, I proposed, was switching to a different chemical formulation, not to a (generally) worse chemical formulation. The number of patients who ended up needing this special treatment was a miniscule percentage of my practice, so I never thought of it as breaking the bank, but rather as personalized medical care.

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