Posted by SLS on August 1, 2005, at 8:16:32
In reply to Re: We need placebo » SLS, posted by Kon on July 31, 2005, at 13:55:43
> > I am not convinced that placebo controls are necessary for medical research. Like I said, there is much debate surrounding this issue.
> I'm sure pharmaceutical companies would love such a scheme.I imagine they would love anything that would bring a drug to market that would make them money without being subject to law suits.
> Wouldn't exclusion of placebo controls result in a high likelihood that ineffective antidepressants/anxiolytics and other drugs be unnecessarily foisted on the public?
This seems to be the prevailing opinion.
I have nothing against using placebo controls, I just think that a new paradigm for evaluating the efficacy of antidepressants is necessary, even if it is merely a change in the selection criteria for people with depressive disorder. Perhaps all that is needed is a rating scale such that a 25% advantage of active compound versus placebo is considered efficacioius. A good way to judge such a rating scale - or any other new investigational paradigm is to evaluate its accuracy retrospectively using the raw data from previous studies. Another use of placebos is to evaluate the validity of a study. Judging placebo response rates versus a known active compound versus the test compound is a good way to isolate failed studies. This is why we don't see reboxetine in the US. The placebo response rate was high and showed equivalancy to Prozac. Prozac is a putative antidepressant often used as a standard rating compound. It has been established as being better than placebo.
> Also not to downplay Dr. Quitkin's findings but even his recent study excluded patients over 65 and those with very severe depression. Dr. Quitkin has also had some associations with Pfizer and been a speaker and on advisory board for Eli Lilly.
Conflict of interest? It would be difficult to tell whether there is a bias on his part. The bulk of his work has utilized tricyclics and MAOIs.
It would be difficult to find people who are not in some way affiliated with drug companies. The NIH has been reviewing its own ethical standards and the affiliations and fundings with private enterprises. They are in the midst of making changes.
> As a pharmacy student, I'm really having trouble to know what the "truth" is wrt efficacy of a given medication and what is best for the patient since trials funded by pharmaceutical companies rarely produce unfavourable results.Moclobemide was found to be ineffective by the FDA according to manufacturer-funded US studies. At least Roche seems to be truthful.
Rarely, if ever, has an antidepressant been approved by the FDA using these results that hasn't ultimately been found to be effective in subsequent clinical usage. Even maprotiline has utility. So far, the system works pretty well, despite complaints by some that studies using placebos don't separate the test antidepressant compound robustly enough to demonstrate efficacy. For the most part, the scientists know that a ratio of 65-70%/30% in favor of the test compound over placebo is a robust value when it comes to antidepressants.
> I'm becoming more skeptical of not just the efficacy of many psychotropics but also anti-cholesterol and anti-hypertensive drugs.
Which ones in particular?
> Can research funded by pharmaceutical companies truly be unbiased or are medical journals becoming an extension of the marketiung arm of pharmaceutical companies as some researchers/academics have argued?
> Dunno...
Me either. You will have plenty of time in your career to more fully explore these issues. I'm sure your future experience with these drugs will help you answer your questions and identify the "duds" when it comes to drugs.
> And I'm saying this even though I do believe that certain drugs are extremely useful and life-changfing for patients. For example, I've had great relief with benzos for my anxiety whereas SSRIS and CBT were totally useless.
Just remember that individual drugs don't have to be effective in a majority of cases to be an important component of an arsenal against a particular disease or set of diseases.
- Scott
poster:SLS
thread:534296
URL: http://www.dr-bob.org/babble/20050728/msgs/536317.html