EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT AVANIR Pharmaceuticals: We consent to the incorporation by reference in Registration Statements Nos. 33-71276, 33-94370, 333-83089, 333-84183 and 333-38094 on Form S-8 and Registration Statements Nos. 33-49082, 33-76094, 333-24549, 333-76641, 333-77925, 333-31442, 333-32776, 333-34958, and 333-35934 on Form S-3 of AVANIR Pharmaceuticals of our report dated December 10, 2001, appearing in this Annual Report on Form 10-K of AVANIR Pharmaceuticals for the year ended September 30, 2001. DELOITTE & TOUCHE LLP San Diego, California December 21, 2001