New Drug For Menstrual Pain On Its Way

By Margarita Nahapetyan

A new experimental drug that is showing promise as a relief for painful menstrual cramps is being developed by British scientists. The drug, known as VA111913, has already completed Phase I clinical trials and is entering Phase II.

The experts have reported that VA111913 works by targeting the cause of menstrual cramps and not just easing the pain. It is known that menstrual cramps, called in medical terms dysmenorrhea, affect more than 50 per cent of women of childbearing age all across the globe. The cramps occur when the smooth muscles of the uterus contract with increasing frequency. The most common symptoms of menstrual cramps are abdominal pain and back pain, but the condition is also associated with nausea, vomiting, sweating, and dizziness.

While half of all women experience some menstrual cramps, between 10 per cent and 20 per cent of the women suffer dysmenorrhea. "It is one of the leading causes of work and school absenteeism in the United States," said Andy Crockett, vice president of business development for Vantia Ltd., the company developing the new medication. Mr. Crockett and his company strongly believe that their drug has the potential to be a real breakthrough.

During menstrual cramps, which are caused by contractions of the uterus, the levels of a hormone, called vasopressin (a powerful stimulant of the uterus particularly at the onset of menstruation), significantly increase. Circulating levels of this hormone are 4 times higher in women with dysmenorrhea when compared to ladies without painful cramps.

The main goal of the experimental medication VA111913, is to block vasopressin. The other medications used by women for pain relief are painkillers and birth control pills, which only address the symptoms of menstrual cramps, and not the cause. Preliminary tests on a small group of female participants showed the new drug to be safe, with no side-effects.

The search for such a potential drug involved shifting through hundreds of chemical compounds and pinpointed to one which provided the needed effects. After that the investigators re-engineered the compound to fine-tune its effects. One modification allowed the drug to be taken orally, as a tablet, rather than being administered in the form of an injection.

The scientists behind the drug said that last year VA111913 successfully passed a testing for becoming a new medication, when the first stage of clinical trials demonstrated that it was safe for the following clinical studies. The next phase of clinical trials is currently underway in the United Kingdom and the United States to analyze how well the drug works to alleviate pain in a group of women who suffer dysmenorrhea. The experts expect results to be available later this year. If studies continue to demonstrate promising results, VA111913 could be available to patients in about 4 years, the scientists say.

The data from a clinical trial was presented on march 23, 2010 at the 239th National Meeting of the American Chemical Society in San Francisco.