Saturday, October 18, 2008


Cymbalta (duloxetine) is one of the newer antidepressants on the market. It is being quite aggressively marketed. I notice various lecturers speaking enthusiastically about its merits.

I am immediately wary of this phenomenon:
-new drug enters the market
-lots of advertising
-lots of money to pay for psychiatrists (some of whom, to my embarrassment, are mood disorders specialists) to give educational lectures about the new drug


-down the road, it is often found that the new drug is not quite as spectacular or good as everyone was thinking...
-most often, the new drug is effective and useful, but not qualitatively better than any other related drug
-the new drug becomes simply another option to try, that might work, or might not, for someone struggling with depression
-the new drug otherwise does not become a "first choice" for someone wanting to start a medication, because the many other drugs in its category (e.g. antidepressants) work just as well, on average

--my reading of the evidence is that duloxetine IS an effective antidepressant. It is an appropriate option for treatment-resistant patients who have tried many other medications. But it is no more effective than its competitors on average. I also do not see any compelling advantages with respect to side-effect profile. And it is more expensive! (of course it has more marketing dollars behind it right now, but should this be a reason to consider it first?)
--it is also being marketed for treating pain syndromes -- yet there are few studies comparing duloxetine with other existing antidepressants, for treating these pain syndromes -- so its apparent advantage may simply be due to the fact that no one has done adequate comparative studies including other treatments.

When looking at references regarding a new treatment, the interested reader should take a look at who the authors are, who sponsored the research (was it the drug company?), how often the authors have been involved by industry-funded research, and how frequently the authors have received money for giving lectures supporting the use of the new treatment. Also, look carefully at what the paper is saying as a conclusion vs. what the data from the paper shows: do the authors try to aggrandize the new drug using words (e.g. "this verifies that... is effective and safe, ... ") while the data from the very same study actually show that the new drug is not actually any better than the old drug?
Also, if the study is comparing one drug with another, are the results biased? For example, did the study protocol only allow a limited, less-than-optimal dose of the comparison drug?

Here are some references:

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