I have a couple of questions concerning the bioavailability of generic versions of brand named generic drugs like Methylin and Dextrostat. As many of you know, for a generic drug to be approved by the FDA the manufacturer of the generic drug must show that the bioavailability of their product does not differ by any statistically significant amount (generally over 20%) from that of the brand name product. That means that a generic version of an innovator drug can be as much as 20% higher or lower in its bioavailability when compared to the innovator drug. I am curious if this same rule applies to the generic versions of the brand named generic drugs?

I used to get a generic version of Dextrostat, which as you know is a brand name generic version of Dexedrine. I found the generic version of the brand name generic to be very inferior to the innovator drug. Could it be that the generic versions of the brand named generic drugs are allowed to be as much as 20% off the actual bioavailability of the brand named generics? If this is allowed for the generic versions of the brand name generic drugs then it would mean that the generic versions of the brand named generics could be as much as 40% off the bioavailability of the original innovator drugs. Unfortunately the actual bioavailability data is never released by the FDA to the public, at least not that I am aware of.

my doctor claims that the issue lies with the inactive ingredients and how the chemistry of them and the agent itself interact and change the action or the body is intolerant (dex in particular dextrostat is a dream compared to the diarrhea assoc. w/ the Barr brand) I am a "brand name snob" myself so I was told the reason in those terms...

You would think that as strict as the FDA is concerning food labeling, and the consumers right to know what makes up their food (most of it anyway), that they would be even stricter concerning the consumers right to know about prescription drugs. I am at a loss to explain why the bioavailability of prescription drugs (or OTC drugs for that matter) are not made available to the consumer, or even made available to Dr's for that matter.:confused:

If I had to guess I would say that the bioavailability data is not available to the public to protect brand loyalty issues. It would make sense that if a generic drug had as much as a 20% higher bioavailability rate over the brand name in question, that the brand name manufacturer would never want anyone to know about that. I really don't want to sound like a conspiracy theorist here, but I can't think of any other reason why the FDA would do this other than to protect the interest of the pharmacuetical companies that own the brands who would be the only ones who stand to lose anything if the bioavailability data was ever made public.

PS If you never hear from me ever again at this site, just know that it's probably because the FDA came and got me after I posted this. :p

lars,
The FDA won't come get you for criticizing them; they get lots of criticism. They get criticized for approving durgs too quick and for holding up approvals on new drugs by apporving them too slow. They might come to get you if you were selling something and making false medical claims for it, but you would have to be making lots of money and getting lots of complaints and ignore the early letters they send to you.:D Then you could pay the fines and sell books full of you medical claims because that would be stopping free speach.:eyebrow: Basically, it takes a lot more than criticism to even get thier attention. Aside from this, the drug companies hold the proprietary info and just have to comply with the FDAs rules to show equivalence:
http://www.fda.gov/cder/guidance/5356fnl.pdf#search='bioavailability%20drug%20produ cts'
Some of them publish the information so that those writing prescriptions have it for comparision.

I was being sarcastic Vickie. I tried to imply that by using that pink smilly at the end of that statement. Sorry for the confusion.



The FDA actually does not come and get anyone as far as I know. They leave that to the FBI, or the DEA, or the federal marshals.

No confusion lars (note my smileys). I was trying to respond in the same fashon and just adding the history of on Gary Trudeau just for the fun of it:D. Sarcasm comes off better when there is a tone of voice to go with it.:p

You're right, it certainlly does come off so much better when there is a tone of voice involved. This happens to me all the time when communicating in this medium.

I remember learning once in a psychology class that something like 80% of human communication is non-verbal. The majority of human communication involves tone, voice inflection, volume, cadence, facial expressions, etc. That being said, I am surprised there are not more confusions than there appear to be in this medium.

Sorry for my confusion then. ;)

No sorry needed. We just needed some extra explanations because of the medium. :D
I just noticed the smileys have explanations if you hold the cursor on them, boy and I slow at this.:eek: