Friday, July 25, 2008

Putting Lipstick on a Pig

Here's another tidbit from Jim Edwards' NRx blog. The background is that many folks taking antidepressants are not enjoying much of a sex life these days so somebody decided that they would add some viagra to the mix for women. Now it is interesting that Pfizer says it is not going to apply to the FDA for permission to sell viagra to women on antidepressants. I guess they decided to fund the viagra for orgasm study out of the kindness of their scientific hearts.

It some ways this is a small story but one of those stories which highlights many of the most pressing issues in pharmaland: research design, pharma funding for research, stretching of the conclusions of the study etc. - Duncan


What's Wrong with That 'Viagra for Women' Study in JAMA?

Plenty.

The media has gone bonkers for this study which purports to show that women with sexual dysfunction brought on by anti-depressant use can get their orgasms back by taking Pfizer's Viagra. Google News had upwards of 476 stories on the study at the time of writing.

(NRx highlighted the Great Orgasm Robbery a couple of days ago. Summary: Anti-depressants rob you of your sex life, subjecting you to dystopian side effects such as the "pleasureless orgasm.")

But the study has problems, bears many of the hallmarks of garbage science, and raises serious questions about why JAMA would publish it.

Among the issues:

+ There were only 98 women in the trial. Forty nine of them were on the placebo and 49 were on Viagra.

+ Only 39 on Viagra actually completed the study.

+ Only 72% of those women reported improvement.

+ Which means that only 28 actual women reported improvement.

So that's it: 28 depressed women have an orgasm and the media goes crazy.

(The good news? At least nobody got cancer.)

The difficulties with the study don't end there.

Pfizer, the maker of Viagra, funded the study. And the doc who carried it out has taken Pfizer money before.

All the women are taking two drugs, an antidepressant plus Viagra, making it difficult to presume whose symptoms were being caused by what.

To qualify, their depression had to be in "remission" (meaning they were the type of patients who were already responding nicely to drugs, treatment, or were getting better on their own).

And the headline stat — that 72% of women taking happy pills plus Viagra get their orgasms back — masks some very odd data lower down in the results tables.

Check out the results in the study that are not about orgasms. "Arousal" got a P value of .81. "Sexual arousal" got .61. "Lubrication" got .64. "Sexual drive" got .40.

If one assumes the .01 value for orgasm was significant, then these other results suggest that although the women got their orgasms back, they didn't get back all the other stuff that goes along with them.

In other words, the one thing that makes this study interesting is that it may have provided hard proof of the reality of the pleasureless orgasm phenomenon.

And can we just remind ourselves of the fact that the reason these women are sexually dysfunctional is because they're taking the kind of drugs — such as Zoloft — that are made by Pfizer, in the first place?

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