Wednesday, September 21, 2005

"No Clear Winners" among antipsychotic drugs...

Derek Lowe's take on the CATIE study.
You’ve probably seen the headlines about the recent NIH-sponsored “CATIE” study comparing five anti-psychotic medications. The result, which is what made the whole thing newsworthy to the popular press, was that it was hard to distinguish among them, with the oldest generic working as well as (or better than) the newer drugs.

But I think that people outside of the medical world are going to learn the wrong lessons from all this. Does this study mean that everyone taking anti-schizophrenia medication should switch to the old generic? Not at all, although if they need to try a different medication, they should definitely consider it. Does it mean that all these newer drugs are unnecessary? No, again...

But I think that this study does make clear that the newer antipsychotics aren’t as good as they should be. The field is a tough one, as I know from personal experience, having played a small role in helping a company spend I’ve-no-idea-how-many millions of dollars to find out that a potential schizophrenia medication didn’t do squat. There’s a lot of room for improvement, and we haven’t been able to improve things very much.

It’s important to emphasize that this was a surprising result. No one expected the side effect profiles of the four “second-generation” drugs to be so similar to the older one (perphenazine), and so similar to each other. That’s one reason that a study like this is so valuable - huge clinical trials that tell you something that you already knew aren’t too wonderful. I think that this is an excellent thing for the NIH to be doing. Tomorrow: what this says about head-to-head trials in general.



4 Comments:

Blogger Greg P said...

I'll have to see the details of the actual study, but there is greater difficulty, and maybe it's impossible, to design a study like this to understand all the aspects of choosing one drug versus another.

I can imagine that a similar study of anticonvulsants would show that our old mainstay anticonvulsants are "just as good" as the newer ones. There was a recent study, not exactly done with the same concept, that showed that whatever anticonvulsant a neurologist chose first was pretty likely to help. So it would seem that, hey, the old ones are cheaper, let's use them first.

Well, there are lots of problems with the old anticonvulsants, and the old antipsychotics. This just isn't going to be a reason to go back to Stelazine and Thorazine. I think people forget what we used to see all the time with long-time users of these.

This will be a study that insurance payors will wield, because they only see patients as financial liabilities.

2:32 PM  
Blogger Greg P said...

Just read the study abstract.

Important to note that about 3/4 of the patients discontinued whatever drug they were on. That, if anything, suggests we need even newer drugs than we have now.

I'm also not sure how much can be learned by focusing on schizophrenia as a treatment population -- a very challenging group by any estimation.

2:40 PM  
Blogger Caltechgirl said...

well, i think that if anything, this study points out that Zyprexa IS doing something. Also, that atypicals are at least as good without some of the same terrible irreversible motor effects.

Clearly the issue for the future is compliance, and how to improve these drugs so as to decrease side effects and therefore increase compliance.

3:51 PM  
Blogger fmodo said...

My concern with CATIE is that they tried to make this a real-life study, but didn't do a real life intervention.

Almost all the patients entered were already on antipsychotic, on average 14 years. Half were on either olanzapine or risperidone.

So what this ends up being is a trial of what happens when you take people off olanzapine or risperidone who may or may not be already doing well, and randomize them to either staying on that drug, or changing to another drug. That is not a real-life decision point.

In real life, we change drugs only when people are not doing well, or wonder which one to start when they are drug-naive.

The danger is that the results of this study will be generalized to the simple conclusion that there is no difference between typicals and atypicals, and I think that could precipitate some very bad policy-making.

7:18 AM  

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