A drug that is regularly used to treat chronic pelvic pain in women has been found to be no more effective than a placebo, a new study has found.

Researchers are now recommending against routinely prescribing the drug gabapentin for women with the condition, as a result of the findings.

Chronic pelvic pain affects up to 24% of women worldwide to varying degrees, while it is also estimated as many as one million in the UK are affected by the condition.

Professor Andrew Horne, lead researcher from the University of Edinburgh, said: “We have been prescribing this drug for many years with little evidence of its effectiveness.

“As a result of our study, we can confidently conclude that gabapentin is not effective for chronic pelvic pain in women where no cause has been identified.

“More research is needed to explore if other therapies can help instead.”

Gabapentin is used to manage many forms of chronic pain. In two separate surveys, 74% of GPs and 92% of gynaecologists said that they would consider prescribing the drug for chronic pelvic pain.

Researchers from the universities of Edinburgh, Birmingham, Oxford and Nottingham tested the drug’s effectiveness in treating chronic pelvic pain through a randomised clinical trial involving 306 women with the condition and no known underlying cause.

As part of the study, 153 women received gabapentin and 153 received placebo for 16 weeks.

Neither group nor the prescribing clinicians knew what they were receiving.

The women were asked to rate their average pain and worst pain, using a scale from zero to ten, on a weekly basis.

Scores were then averaged for the drug and placebo groups.

The team found there was very little difference between the reported pain in both groups.

However, the group that received gabapentin reported experiencing more side-effects – including dizziness, drowsiness and changes of mood – than the placebo group.

The researchers say that gabapentin should no longer be considered in the treatment of chronic pelvic pain where no cause has been identified.

They also argue other avenues of treatment should be explored, such as different drugs, physiotherapy and cognitive behavioural therapy.