Intrinsa

Intrinsa is a testosterone patch by Procter & Gamble designed to treat Female Sexual Dysfunction (FSD).

Background
FSD covers at least four different conditions: problems with desire, sexual arousal, achieving orgasm, and genital pain. The patch aims to increase libido in women. Doctors have used a range of other treatments for women, including various hormones, antidepressants, and male impotence drugs like Viagra, Levitra, and Cialis. According to a P&G survey on female health 30 million women are naturally menopausal, 3 million are distressed by their lack of sexual desire, and 20% of 25 million women who are surgically menopausal are distressed.

Method
Intrinsa works by releasing the hormone testosterone through the skin into the bloodstream. In women, testosterone is naturally produced by the ovaries and the adrenal gland. However, levels of the hormone decline with age, sometimes dramatically so after the menopause or after a hysterectomy. Testosterone therapy is systemic and needs to be applied over a period of weeks or months to have a noticeable effect. P&G licensed the treatment to Watson Pharmaceuticals.

The amount of testosterone in the patch, 300µg/24hrs, is significantly lower than in testosterone patches for men. The patch is virtually transparent and about the size of an egg and is worn just below the navel and changed twice weekly.

Testing and release to market
In P&G's studies over six months of surgically menopausal women, those who received a placebo said satisfying sexual activity increased by an average of 19%, vs. a 73% increase for Intrinsa patch users. In the placebo group, women had an average increase in satisfying sexual episodes of 0.5 per month, while those with patches had an average increase of 1.9 episodes per month.

The patch was granted a license from the European Medicines Agency in July, and is available on Britain's National Health Service from March 2007. It will initially only be available on prescription for post-menopausal women with diagnosed sexual problems.

However, in December 2004 the United States the 14-member Food and Drug Administration (FDA) advisory committee, plus voting consultants, for Reproductive Health Drugs unanimously rejected Procter and Gamble's fast-track request for Intrinsa citing concerns about off-label use. In Canada, post-menopausal women have been able to obtain government-approved testosterone treatment since 2002. In Australia, post-menopausal women can use Organon testosterone implants which have to be surgically inserted and last from three to six months.