Science News: New Drug to Boost Sexual Desire
Women now have another option to treat their loss of desire for sex. The FDA recently approved Vyleesi (bremelanotide) to treat hypoactive sexual desire disorder (HSDD) in premenopausal women. HSDD is more commonly known as low libido or loss of sexual interest and about 1 in 10 women premenopausal women are affected. From a diagnostic perspective, HSDD is characterized by low sexual desire that causes marked distress or interpersonal difficulty and is not due to a co-existing medical or psychiatric condition, problems within the relationship or the effects of a medication or other drug substance.
Vyleesi activates the melanocortin receptors, but the mechanism by which the drug improves sexual desire is unknown. Unlike other drugs like Viagra that increases blood flow to sex organs, Vyleesi is thought to increase a woman’s desire by changing the mix of neurochemicals involved in female sexual arousal — specifically the “feel good” chemical dopamine.
Vyleesi works by being injected under the skin of the stomach or thigh 45-minutes before a woman wants to have sex. The timing may require some experimentation and it remains to be seen whether women will be comfortable injecting themselves. The FDA does not recommend that patients use more than one dose within 24 hours or more than eight doses per month, and they advise discontinuing treatment after eight weeks if patients do not report an improvement in sexual desire and associated distress.
As reported by the FDA, the most common side effects of Vyleesi are nausea and vomiting, flushing, injection site reactions and headache. About 1% of patients treated with Vyleesi in the clinical trials reported darkening of the gums and parts of the skin, including the face and breasts, which did not go away in about half the patients after stopping treatment. Patients with dark skin were more likely to develop this side effect. Vyleesi is also not recommended in patients at high risk for cardiovascular disease as it may increase blood pressure temporarily.
The effectiveness and safety of Vyleesi were studied in two 24-week, randomized, double-blind, placebo-controlled trials in 1,247 premenopausal women with acquired, generalized HSDD. Most patients used Vyleesi two or three times per month and no more than once a week. In these trials, about 25% of patients treated with Vyleesi had an increase of 1.2 or more in their sexual desire score (scored on a range of 1.2 to 6.0, with higher scores indicating greater sexual desire) compared to about 17% of those who took placebo. Additionally, about 35% of the patients treated with Vyleesi had a decrease of one or more in their distress score (scored on a range of zero to four, with higher scores indicating greater distress from low sexual desire) compared to about 31% of those who took placebo. There was no difference between treatment groups in the change from the start of the study to end of the study in the number of satisfying sexual events.
While there are more than two dozen drugs for enhancing sexual desire in men on the market, with the addition of Vyleesi there are now only two available women. The other drug, Addyi, has had limited success due to safety concerns and the steep price. The FDA has come under pressure in recent years to address this gap, and responded by holding public forums and seeking expert opinions on how best to judge the effectiveness of sexual dysfunction drugs for women. With the approval of Vyleesi, the organization emphasized its commitment to women’s sexual health.
More treatments addressing women’s sexual desire are in development. Here’s to hoping that safe and effective treatments will be available not only for premenopausal women, but for peri and postmenopausal women as well.