EXHIBIT 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Prospectus constituting part of this Amendment No. 2 to this Registration Statement on Form S-3 of our report dated February 5, 1999 appearing on page 43 of Triangle Pharmaceuticals, Inc.'s Annual Report on Form 10-K for the year ended December 31, 1998. We also consent to the reference to us under the heading "Experts." PRICEWATERHOUSECOOPERS LLP Raleigh, North Carolina November 2, 1999