An experimental new drug may ease menstrual cramps by targeting the cause rather than the symptom of the pain, say scientists.
"We hope that the drug will provide a more effective treatment option for millions of women worldwide with this painful condition," said Andrzej R. Batt.
Batt pointed out that Menstrual cramps, known in medical terms as dysmenorrhea, affects between 45 and 90 percent of women of child-bearing age, In addition to pain in the abdomen and back, symptoms may include nausea, vomiting, sweating, and dizziness.
Existing treatments for the condition include pain-relievers, anti-inflammatory drugs, and oral contraceptives that stop menstruation.
However, these treatments are ineffective in almost one-third of women with moderate to severe cases. Some of them relieve only the symptoms, rather than targeting the underlying cause of dysmenorrhea, and may have unwanted side effects such as mood alteration and stomach upsets.
Menstrual cramps are caused by contractions of the uterus during menstruation. In dysmenorrhea, the uterus contracts with increased frequency, causing unusually severe, cramping pain.
The cause, scientists believe, is increased blood levels of the hormone vasopressin, which plays a role in regulating contraction of the uterus. The Vantia scientists reasoned that blocking this hormone might relieve dysmenorrhea..
Their search for such a potential drug involved shifting through hundreds of chemical compounds and led to one with the desired effects.
Scientists then re-engineered the compound, known by the code word, VA111913, to fine-tune its effects. One modification allowed the drug to be administered orally, as a pill, rather than in an injection.
Batt said that last year VA111913 successfully passed a landmark toward becoming a new drug, when the first stage of clinical trials showed that it was safe for further clinical studies, with no apparent ill effects.
The next phase of clinical trials is currently underway in the U.K. and the U.S. to evaluate how well it works to control pain in a group of women with dysmenorrhea. Investigators expect results to be available later this year.
If studies continue to show promise, the drug could be available to patients in four years, the scientists say.
The scientists described the study at the American Chemical Society (ACS) 239th National Meeting, being held here this week.