A pill for women with sexual dysfunction, similar to Viagra used by men, has been approved by a drug regulator in the United States.

The drug, Addyi, will be prescribed for patients with a condition known as acquired, generalised hypoactive sexual desire disorder (HSDD), or sudden and severe loss of libido.

The non-hormonal drug works by targeting neurotransmitters in the brain to boost the libido of women with a prescription that it should be taken once daily, at bedtime.

By working on neurotransmitters such as dopamine and norepinephrine that the brain uses to transmit information, the drug enhances sexual desire.

Health experts define HSSD as persistent or recurrent lack of interest in sex and can develop in women who previously were sexually active, causing distress and relationship problems “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.”

“Today’s approval provides women distressed by their low sexual desire with an approved treatment option,” said Janet Woodcock, M D, director of the Food and Drug Administration’s  (FDA) Center for Drug Evaluation and Research.

However, Dr Woodcock explained that the drug that can only be used by women who have not attained menopause and would only be available from certified health care professionals and certified pharmacies to prevent misuse.

Sprout Pharmaceuticals based in North Carolina manufactured the drug also known as flibanserin yet its approval by the US FDA comes with a caution that it should not be taken with alcohol due to the risk of serious side effects.

In the research phase, women taking flibanserin reported on average 4.4 sexually satisfying encounters per month, compared to 3.7 in a placebo group and 2.7 before beginning the study.

Side effects of the drug include low blood pressure, loss of consciousness, dizziness, somnolence (sleepiness), nausea, fatigue, insomnia and dry mouth.

However, patients are advised to discontinue treatment after eight weeks if their sexual desire does not improve and associated distress.

Dr Woodcock cited the approval as a first step in providing treatment options for women with low sexual desire.