A Follow Up Note on Qnexa and Obesity

First, in response to a few questions that folllowed my Qnexa post (also the associated post on my Psychology Today blog).

On Feb 22 the FDA Advisory Committee voted to recommend approval - which usually signals that approval will be granted; but the final decision is to be made mid April. In other words, as of now, Qnexa does not have FDA approval for obesity.

But these questions about approval stirred my curiosity about the level of buzz Qnexa has generated.

How can one gauge that?

Well here is what I did.

I decided to use a reputable medical meta-search engine and compare the number of hits for Qnexa with the number of hits for some other new medication for a different indication.

I've chosen Trip Database as my meta-search engine. Trip Database not only provides a very solid search tool but also presents the search results in a format that makes it easy to differentiate between the different types of  retrieved data (eg, original research, guidelines, textbooks or news). I then compared the search results for "Qnexa and obesity" with the search results for "asenapine and schizophrenia".

Why choose asenapine? Asenapine is neuroleptic that got FDA approval for the treatment of schizophrenia back in 2009. As such it's still a relatively new medication (for a fair comparison with the very new Qnexa) and at the same time it's been around for long enough to generate some news (or so you'd think).

Why choose schizophrenia? As, similar to obesity, it represents another major public health issue. In case you don't know the most recent global burden of disease data form the World Health Organization place schizophrenia at #9 on the top 20 causes of disability word-wide. For comparision sake I should also mention that obesity, while a major health issue in the US, doesn't even make it on the same world wide top 20 list.

What are the results?

In a couple of my prior posts I used the "asenapine and schizophrenia" example to discuss on how to search for the best evidence (Tripping for Evidence Part 1 and Part 2). So last night I just re-run the same search for "schizophrenia and asenapinelast" on Trip Database and I got 20 hits (search results as of March 12, 2012). The "Qnexa and obesity" search on the same site returned 32 hits total.

So we got thirty percent more hits (ie, publications) for a drug that is yet to get FDA approval.

But it gets even more interesting than this: from the 20 asenapine results about 15% (N=3) were news reports. For Qnexa 100% (N=32) of the hits are news results.

Granted, this are proxi measures at best. However, as a indirect measure of the buzz out there when it comes to different public health issues, in this case, schizophrenia and obesity, the results are pretty telling.

And the story they tell is that as a society we seems to be overinterested in issues related to weight and body image. That in itself might be part of the problem.

© Copyright Adrian Preda, M.D.

Tripping for Evidence - Part 2

(Please go HERE for Part 1)

Nowadays everybody is using PubMed.

Not a bad choice but not necessarily the place where you would want to start. PubMed is the search engine for Medline, an indexed bibliographic database curated by the U.S. National Library of Medicine. Which means that the amount of evidence is, at the same time, impressive and overwhelming. You need to know how to find what you are looking for when faced with such an enormous amount of data.

So, given the choice, why not making it easier on yourself? How about getting some help, ie, letting someone else do some of the tedious work of filtering and grading the evidence before you try your hand at it.

Suppose that you just saw a patient with a diagnosis of schizophrenia, suffering of chronic auditory hallucinations on his current regimen of ziprasidone (Geodon) and divalproex (Depakote). You have tried all the others second generation antipsychotics and a few of the first generation - they were either only partially effective or poorly tolerated. The patient tells you he's heard of asenapine (Saphris), a new drug that has been recently approved for the treatment of schizophrenia. He asks if you would consider switching him to this new drug.

You've read the news about asenapine but didn't get a change to review the litterature. You tell him you will look it up and then discuss the options.

Before searching Medline, which you know will bring uo quite a few articles, you decide to call in your helpers. Their names are Trip Database and SUMSearch.

What do you find?

Your SumSearch, well, search for the simple "asenapine and schizophrenia" search term returns 31 hits under the "Original Studies" tab, 2 hits under the "Systematic Studies" tab, and 0 hits under the "Guidelines" tab (search conducted on Tuesday, 12 March 2012 05:55:34 at SUMSearch). A similar TripDatabase search returns 20 hits, classified according to the level of evidence.

Compare that with the 60 hits returned by the same strategy on PubMed.

This is actually one of the instances where less is more.

When time is of essence (think busy outpatient clinic or evidence-based answers needed pronto for the inpatient rounds) what defines a good search is not sensitivity but specificity. Less hits that are highly informative are preferred to more comprehensive but less specific coverage.

Ergo: let's take a TRIP and SUM the search.

© Copyright Adrian Preda, M.D.