I think purple and yellow colors are pretty. Whew, glad to get that off my chest.
In May, 2008, the FDA approved the marketing of desvenlafaxine, which is the "newest in the class of medications known as SNRIs (serotonin-norepinephrine reuptake inhibitors)" - (www.pristiq.com). What the website neglects to mention is that desvenlafaxine is not new, rather, it's old. How old you ask? Well, as old as venlafaxine (better known by his Indian name: Effexor). But desvenlafaxine has a big "DES" before the word venlafaxine, so how can it be the same?
This trick is not new to drug companies. When a beloved drug is about to lose its patent (Effexor is generic, and Effexor XR will be by 2010), it costs less, and is prescribed less. Instead of investing money in "development and research" of new classes of drugs that might have something different to offer (major university don't help in that respect either), manufacturers patent a similar version of the drug, in this case, the active metabolite of venlafaxine (metabolite being what the drug is turned into after first-pass metabolism by the liver). Invega (paliperidone), who you'll recognize by his many adds in Archives of General Psychiatry, is the active metabolite of Risperdal (risperidone).
Well surely, this drug offers many new improvements over the original. No. If venlafaxine is turned into desvenlafaxine by the liver, then they're identical. How about side effects? No. How about the number of pills you have to take? No. And No, No, No. Those last three No's are for you. Use them anyway you want.
However, I must say that the research is quite robust. The mean decrease from baseline in the Hamilton rating Scale for Depression (i.e., the best damn rating scale ever!) in one study was 9.5 for placebo and 11.5 for 50mg of desvenlafaxine and 11.0 for 100mg. The second study showed a decrease of 10.7 for placebo (Go Placebo!) and 13.2 for 50mg of desvenlafaxine and 13.7 for 100 mg (damn!). That's a jaw dropping 1.5-3 points. To whom do I send my $122.76 for a one months supply? If you haven't seen the HAM-D, it looks like this (1). This is a slightly longer version (the clinical trials used the 17 question version). You can have a change on a single question, and just like that, you're better than placebo. That's not what actually happened, but I think I made my point.
The next step for Wyeth (the manufacturer) is advertising. I just saw the first advert in this month's (August 2008) Archives of General Psychiatry (along with the string of Invenga adverts). It's also cheaper than both Effexor and Effexor XR ($157.20 and $136.00 for the latter). That's until they're generic for a period of time, in which case they will be cheaper, but not by much (generic venlafaxine is $120).
Here's the link to the prescription info (2) . Or you can just check out the website: http://www.pristiq.com/ - It has a lot of pretty happy white people and one happy black woman. It's amazing the difference three points can make.