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Provigil and Nuvigil
MaxSleep posted:
For anyone with questions about the differences between Provigil and Nuvigil, and whether they should switch:

Provigil is actually a mixture of two molecules that are mirror images of each other. Only one of these is the active molecule; the other has little to no activity. Many drugs are formulated in this way, primarily because it is cheaper to produce. However, drug companies have also found another way to use this to their advantage.

The patent on Provigil will be expiring soon. This means that other companies will be able to sell you the exact same substance (the generic drug) at a drastically reduced price. Obviously, this is bad news for Cephalon (the company who owns the patent). However, they have made use of a loophole that is starting to be exploited by drug companies. A new patent will be issued if a "new" drug is produced that contains only the active molecule and not its mirror image. This formulation is given a different name, and a marketing campaign is launched to promote the "new" drug. Claims are made that the new drug is twice as effective, because you can take half as much to get the same effect. Of course, all this really means is that you are getting the same exact amount of the active molecule, but none of the inactive one. In this way, Celexa became Lexapro, Prilosec became Nexium, and Provigil became Nuvigil.

Now, this does not necessarily mean that the effects of Provigil and Nuvigil are identical. The "inactive" chemical may still have a biological effect, either positive or negative. However, this is generally due to random chance; in almost every case, this secondary molecule has little to no effect on the target(s) of the active form.

If you are on Provigil, should you switch to Nuvigil? It depends why you are switching. If you are experiencing side effects but want to stay on the drug, there is some chance that a formulation without the mirror image molecule will reduce those, since they might be due to random, off-target effects. However, if you have developed a tolerance to Provigil and are hoping that Nuvigil will be more effective, you are likely to be disappointed. You are not adding any new chemicals to your treatment, only removing some (probably unnecessary) chemicals that you used to be taking.

That said, there's probably no harm in trying Nuvigil, and it's unlikely to be *worse* than Provigil. And for now, both are patented, so the prices will be comparable. However, once generic Provigil (modafinil) is available (April 2012, according to Wikipedia), consider carefully whether this difference is worth the extra cost.

P.S. A disturbing number of doctors are unaware of these differences, or they do not fully understand them. Also, in my experience, doctors do not generally respond positively to a patient rejecting one of their ideas, even if the reason is valid. It may be worth a (possibly temporary) change to keep the peace. Also, they may have a ton of free samples of Nuvigil that you could take advantage of, given to them as part of the Cephalon marketing campaign.

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Kellyjo82 responded:
I had good results with provigil after my first sleep study. After my 2nd sleep study my doctor thought I needed something stronger so he recommended nuvigil. I hated it. It felt like my brain was literally swelling all around the inside of my skull. It actually scared me. I would go off of it and see if it was from something else and it stopped. It was like clock work.. I would take the pill and half hour later my head would hurt so bad.

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