More women are dying from prescription painkiller overdoses than ever before, highlighting what the Centers for Disease Control and Prevention calls a growing public health epidemic.

The CDC study shows that while men are still more likely to die of overdoses, the number of deaths among women increased five-fold in the last decade, four times more than deaths in women from cocaine and heroin combined, says CDC director Tom Frieden. About 12% of these deaths were suicides, CDC experts said.

The rate of prescription drug overdose deaths of women increased 400% from 1999 to 2010, compared with an increase of 250% for men. More men die of prescription painkiller overdoses — about 23,000 in 2010, compared with 15,300 for women.