Opinions - Mexican Alprazolam (generic) vs. American Alprazolam (generic)

[WhoreHouse]

SWIM thinks that their is a difference in the potency of the two. The American being slighty more effective. Do you think this is true or more of a placebo effect?

[bman1]

They are the same drug with the same affects. One might feel a sligh difference because of binders and absorbtion rate. But a 10mg valium is a 10mg valium

[Laudaphun]

One must keep in mind that in the U.S. the drugs are regulated. The FDA requires that generic versions to work as quickly and effectively as the brand name. There is a slight +/- % allowed in efficiancy and effectiveness measured by two parameters.

The two parameters that we look at to determine bioequivalence that are derived from plasma concentrations are area under the plasma concentration time curve, or AUC, and maximum plasma concentration that's achieved after a dose, or Cmax. These are very simple pharmacokinetic parameters. You don't have to be an expert in pharmacokinetics to be able to figure them out. They are quite simple. They are not really overly dependent on any model or assumption. The AUC relates to the extent or how much drug is absorbed from a dosage form. Cmax is related to the rate. With a difference in rate, the maximum concentration or peak goes up or down so that it's sensitive to the rate of drug input from the formulation. You could conceivably have two formulations that would deliver the exact same amount of drug to the body but do it at very different rates. One could be fairly rapid with a high peak and one could take quite a bit longer with a lower peak. Those would not be considered equivalent if they were considerably different from each other.

We assess these parameters by using 90% confidence intervals and these must fit between 80% and 125%. It's a misconception by most people, consumers and physicians alike, that we allow the mean of the data that we get from our studies to be as much as 80% below or 125% above. That's really not true. Because we're using these confidence intervals, the mean of the data never really gets close to these bounds. That's a very common misconception.

Basically by law, in the U.S. generics must achieve between 80% to 125% of maximum plasma concentration as the brand name. However in Mexico, I'm not sure what laws govern the production of generic drugs. While I know nothing of Mexico's laws regarding the manufacture of prescription drugs, I wouldn't necessarily count on a 10mg generic Mexican diazepam to be equal in potency as a U.S. brand or generic. Actually, while people generally think in the U.S. that brand names are always better than a generic, it is entirely possible for a generic to achieve a slightly higher max plasma concentration than the brand name, while at the same time it is also possible that the generic could also achieve a slightly lower max plasma concentration. As stated in the post above the difference in binding agents and fillers would be the likely cause of this.

But basically, if the Mexican pill actually contains 2mg alprazolam then it would be equivalent to any other pill that contained 2mg alprazolam, taking into consideration the "possibily" slight difference caused by the use of different binding agents and fillers. Also keep in mind when you are not familiar with the laws in which the pills are manufactured, you can not necessarily be 100% sure that a pills that claims to contain 2mg alprazolam actually contains 2mg alprazolam. Just food for thought.

I will try to upload the entire pdf version of the document where the above italisized information was cited from. I would not be permited to post a link as would be a violation of the laws the govern what SWIM's may and may not do on this website.

EDIT: Full pdf uploaded to: http://www.drugs-forum.com/forum/loc...=4835&catid=69

Reputation Comments on this post:

	Nice!
	Very informative