Roy Moynihan’s book details pharmaceutical companies’ plans to push the idea of female sexual dysfunction all the way to the bank.

In December, a small local biotech named Apricus Biosciences decided to put substantially all its eggs in one basket: male and female sexual disorders. But in tackling male erectile dysfunction, Apricus faces stiff competition from pharmaceutical giants Eli Lilly (Cialis), Pfizer (Viagra), and Bayer (Levitra). Trying to relieve female sexual dysfunction presents a completely different problem: many critics think this so-called disorder, although officially recognized by the American Psychiatric Association, is an industry marketing ploy to peddle potions of dubious value.

Apricus is trying to get regulatory approval around the world for Vitaros, a topical treatment that, spread on the penis, is supposed to bring an erection faster than competitors’ products. It supposedly works well with men who don’t respond to Viagra, but it has only been approved in Canada.

Erectile dysfunction is a market of close to $5 billion. Two years ago, Cialis passed the originator, Viagra, in sales, greatly because it boasts of a high-powered drug that can be effective for up to 36 hours. In France, it’s called “le weekender.”

In the United States, the Food and Drug Administration has never given the okay to any medical treatment for female sexual dysfunction, which comes in several varieties: sexual arousal disorder (the one Apricus is going after), orgasmic disorder, sexual aversion disorder, sexual pain disorder, hypoactive sexual desire disorder, and some other medically related conditions. Powerful companies, such as Procter & Gamble and Germany’s Boehringer Ingelheim, have flopped trying to exploit this field.

But Apricus thinks there can be a $4 billion market and believes its Femprox, meant to create clitoral enlargement, can be among the successful treatments.

“Female sexual dysfunction is a real disease,” says Dr. Bassam Damaj of La Jolla’s Innovus pharmaceuticals.

Sexual dysfunction in women, says Edward Cox, vice president of Apricus Biosciences, “is indeed a complex, multi-factoral condition.”

Last November, Apricus’s chief executive, Dr. Bassam Damaj, left the company for undisclosed reasons. In January, Damaj became chief executive of Innovus Pharmaceuticals, which then moved to La Jolla. Damaj is loaning Innovus half a million dollars to fund product development, including treatments for female sexual dysfunction. The company is in negotiations to acquire a topical over-the-counter product that would increase blood flow to the clitoris, says Damaj. Innovus bought the non-American rights to an over-the-counter product, CIRCUMserum, that increases sensitivity of the penis. (It doesn’t cause erections but makes them more fun.)

Just think: we used to call men impotent and women frigid. Now their bedroom shortcomings have fancy medical names and supposed cures.

Treatments for erectile dysfunction are generally satisfactory. But controversy rages over female sexual dysfunction. A 2010 book by Ray Moynihan and Barbara Mintzes, Sex, Lies & Pharmaceuticals: How Drug Companies Plan to Profit from Female Sexual Dysfunction, opened some eyes. “Women’s sexual difficulties are being repackaged as symptoms of a new disorder,” say the authors, flagellating the “marketing machine” that plans to exploit a condition that is highly complex physically, psychologically, and interpersonally and may not respond to the expensive treatments. To hawk sales, pharmaceutical companies have come up with diagnostic tests “aimed at measuring disorders that may not in fact even exist,” says Moynihan.

In Psychology Today last month, Dr. Allen Frances, an emeritus professor at Duke, slammed “disease mongering of female sexual disorders.” Female sexual dysfunction is “mostly a concoction of lusty males, sex disorder clinicians and researchers (mostly male), and drug company sales gurus,” wrote Frances.

He quoted Tamara Kayali, a postdoctoral researcher at Dalhousie University in Nova Scotia, who wrote that “previously proffered products all turned out to be ineffective duds, but as the female sexual disorders represent such marketing gold, the companies keep coming up with new contenders and new hype that women have a sexual disorder that needs treatment.” She pointed out that if a woman is disinterested in sex or doesn’t find it enjoyable, “the problem may not be a biological or mental illness. Perhaps the relationship needs some adjustment or her man needs some skills training.”

Perceptively, she cited one American study that showed that 29 percent of women said they “usually” or “always” experience an orgasm during sex, while more than twice as many, or 60 percent, reported having an orgasm from masturbation. The problem may be that too many men are lousy lovers. Said Kayali, “So while it may be kind of scientists to attempt to develop a drug that enables women to gain more pleasure and satisfaction from sex, it would be even kinder to women to look into a drug that made men better at it.”

The Mayo Clinic notes that women’s sexual problems may result from physical conditions such as arthritis, urinary and bowel difficulties, pelvic surgery, and — yes — headaches. Postmenopausal changes can weaken the sex drive, as can depression, anxiety, heart and blood-pressure diseases, and liver or kidney failure. Drugs such as antidepressants and antihistamines can decrease sexual desire and response.

The Harvard Medical School notes that a man’s erection is a quantifiable event, “but a woman’s sexual response is qualitative… it can’t be measured objectively. Without an empirical standard by which to assess female sexual function, it would seem difficult, if not impossible, to come up with criteria for female sexual dysfunction.”

Damaj of Innovus disagrees with the critics: “Female sexual dysfunction is a real disease,” he says. The market for it “is estimated to be larger than the male erectile dysfunction market.” Edward Cox, Apricus’s vice president of corporate development, says female sexual dysfunction “is indeed a complex, multi-factoral condition with anatomical, physiological, medical, and psychological components. [But] significant numbers of American women — up to 40 million, by some estimates — are turning to their physicians seeking a medical solution.”

Financially, both companies are troubled. Apricus lost $31.7 million last year, worse than the $18.1 million loss of 2011. The cumulative loss since the company’s inception is a stunning $251.2 million. The stock hit $294.39 in 2000 but Monday closed at $2.89. Innovus, which does not yet have a listing on Nasdaq, has never had revenue from a product. The stock closed Monday at 46 cents.

Bottom line: attacking sexual dysfunction can be dyspeptic.