Large pharmacy chains involved in a major lawsuit over the opioid epidemic have sued doctors in Ohio, claiming they are to blame for the nation’s drug crisis.

The chains—Walgreens, CVS, Rite Aid, Walmart, Discount Drug Mart and HBC—filed complaints against unnamed doctors in two Ohio counties. The companies face a federal trial, which is scheduled to begin in October, The Washington Post reports.

The companies argue the doctors and other prescribers should be required to pay some of the penalty if the pharmacy chains are found liable.

Last year, drug makers and distributors agreed or were ordered to pay hundreds of millions of dollars in opioid settlements and one court verdict. So far, the major pharmacy chains have not been held liable, the article notes.