EXHIBIT 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Acura Pharmaceuticals, Inc.

Palatine, Illinois

We hereby consent to the incorporation by reference in the Prospectus constituting a part of this Registration Statement of our report dated March 31, 2017, relating to the consolidated financial statements of Acura Pharmaceuticals Inc. appearing in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016.

/s/ BDO USA LLP

Chicago, Illinois

November 17, 2017