On face value, if you read Anita Clayton's Huffington Post piece entitled “The FDA, Sexual Dysfunction and Gender Inequality,” you could not come to any conclusion other that the FDA is overtly sexist.

Dr. Clayton, a Professor of Clinical Obstetrics and Gynecology at the University of Virginia School of Medicine, is not subtle about her premise. Her essay begins:

“Throughout our society,gender inequality is evident -- in politics, employment, pay, attitudes and drug approvals, specifically medications for female sexual dysfunction (FSD).While sexual dysfunction is more common in women than in men (43 percent vs. 31 percent), the FDA has approved 24 treatments for sexual dysfunction in men* and ZERO for [women].”

If these numbers are correct, how could it be otherwise?

Given her position at a top-notch medical school, I would be quite surprised if Dr.Clayton was anything but a superb physician and educator.

But her strength is not math. And if you look beneath the surface, a very different picture emerges.

First, lets look at the actual number of drugs that have been approved.Twenty-four isn’t even close. The real number is five. Maybe six, depending on some subjective interpretation.

Why the discrepancy? Dr. Clayton counts identical drugs with different brand or generic names as unique drugs, which inaccurate and misleading.  Are Bayer aspirin and CVS acetylsalicylic acid—the chemical name for aspirin—different drugs? No way. Yet, it is this Enron-like math that Dr. Clayton uses to support her premise.

For example, the most common drugs for erectile dysfunction (ED) Cialis, Levitra and Viagra are each sold under three names—each with FDA approval. Does this add up to nine drugs? No. It is three. Calling a pill by a different name does not make it a different drug. The fourth and newest member of this class is called Stendra (avanafil, Staxyn).

So, in reality, there are four different drugs in the Viagra (phosphodiesterase-5 inhibitor) class—not 12. They all work by the same mechanism—by augmenting the action of the neurotransmitter nitric oxide, which in turn relaxes the muscles of the penis, permitting additional blood flow. Following sexual arousal, an erection then becomes possible.  Although all four operate by the same mechanism, they are structurally different drugs.

Alprostidil—a powerful endogenous vasodilator is also commonly used. It is a member of the ubiquitous prostaglandin family of chemical messengers. Its chemical name is prostaglandin E1, but it is sold in different formulations—injectable and transurethral. There are six approved products containing the same active ingredient. Six names, but one drug. We are now up to five.

After this, the tally becomes somewhat subjective. Papaverine and phentolamine are sometimes used in conjunction with Alprostidil, but their use is off-label—not FDA approved for MSD. These don’t count. There are others that are not approved or simply don’t work.

It is not clear that testosterone is useful for male sexual dysfunction, so it is reasonable to question whether the 29 different products—all consisting of testosterone or methyltestosterone as the active ingredient—even count as two, let alone 29.

And even if it does work, testosterone replacement can be roughly viewed as the male equivalent of hormone replacement therapy (HRT) for women, so let’s say that these cancel each other.

Finally,there is one FDA-approved drug to treat a congenital condition called Peyronie's disease. Peyronie's is inflammatory connective tissue disorder characterized by the formation of plaques and scar tissue. It results in a permanent and painful upward curvature of the penis. Is this really a treatment for MSD. I think not.

So, by my count the number of different products in use (approved or not) is not 24, but is actually north of 50. But the number of FDA-approved drugs for MSD is five.

OK, some may argue that even 5-0 represents a gender bias, but I don’t buy it.

Although there is a psychological component to ED, the primary physiological cause of male sexual dysfunction is circulatory deficiency—a straightforward, and pharmaceutically addressable condition. This is why the drugs work.

Female sexual disorder a/k/a hypoactive sexual desire disorder (HSDD)— diminished sex drive— is a whole different (and far more complex) problem, having hormonal, neurochemical and psychological components. It defies logic to even compare the two, since they are very different conditions. It makes as much sense as assigning bias based on the relative effectiveness of treatments for breast and prostate cancers.  If available treatments for the two cancers are better for men or women, does that mean that the FDA is biased in this case?

Of course not. But when scientific issues turn into “rights” issues, logic goes out the window. Diseases and conditions do not care about equality. Some have no useful therapies (Alzheimer’s) and some have very good ones (childhood leukemia). Is this an example of bias against older people? You cannot force a disease to yield to sociological pressures. Science simply doesn’t work that way.

And does anyone really believe that if there was an effective treatment for female sexual disorders that companies wouldn’t be climbing all over each other to sell it? Such a therapy would be a license to print money. No effective therapies are available for afflicted women because their problem just happens to be far more difficult—not because anyone is favoring men.

But, as in the rest of life, politics can trump all.  Women’s rights groups have recently begun focusing on getting a drug called flibanserin, a drug for HSDD approved by the FDA. Loribeth Weinstein, CEO and executive director at Jewish Women International recently said “The need for advocacy in support of a balanced flibanserin review was due to a sharp contrast and disparity around gender when it comes to the evaluation of drugs that address the issue of low sexual desire.”

Is there anything to this? You decide.

Flibanserin was dropped by Boehringer Ingelheim in 2010 following a negative FDA report. The FDA advisory panel voted 10-1 against approval because the drug did not perform any better than placebo. And there were side effects like dizziness, nausea and fatigue more than offset any benefit from the drug.

In other words, exactly the same type of recommendation that could be expected for any drug—whether for cancer, AIDS, or heart disease—that failed to demonstrate what it takes to gain approval: A favorable benefit to risk ratio.

So,was the FDA being sexist? Absolutely not. They were doing their job properly.

After Boehringer Ingelheim discontinued their clinical trials, Sprout Pharmaceuticals picked up the ball and are continuing to run clinical trials.

I wish them well. But if their drug is going to work, it will do so based on its own merits—not from political pressure. You can lobby all you want, but it won’t make a lousy drug any better.

Schlitz beer front page image: The Invisible Agent