Data is used for the first time to show regional differences in the uptake of a single medicine – sodium valproate – and the potential benefits are striking say researchers

Scientists have created a unique map of England and Wales that reveals detailed variations in the use of a single medicine. The drug is sodium valproate, a treatment for severe cases of epilepsy that is also known to cause health problems for pregnant women.

The findings show drops in the use of the drug, in response to warnings about its effects, but the map reveals clear differences in dispensing patterns to women of child-bearing age, with the highest rates being found in local authorities in the north-west and across coastal regions in the east. These variations highlight potential inequalities that need further investigation, the researchers warn.