LA JOLLA PHARMACEUTICAL COMPANY
                                  EXHIBIT 99.1


                           CERTIFICATION PURSUANT TO
                            18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                 SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Each of the undersigned, in his or her capacity as an officer of La Jolla
Pharmaceutical Company (the "Registrant"), hereby certifies, for purposes of 18
U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, that:

   o the quarterly report of the Registrant on Form 10-Q for the quarter ended
     June 30, 2002 ("the Report"), which accompanies this certification, fully
     complies with the requirements of Section 13(a) or 15 (d) of the Securities
     Exchange Act of 1934; and

   o the information contained in the Report fairly presents, in all material
     respects, the financial condition of the Registrant at the end of such
     quarter and the results of operations of the Registrant of such quarter.

Dated:  August 13, 2002

                                            /s/ Steven B. Engle
                                            -----------------------------------
                                            STEVEN B. ENGLE
                                            Chairman and Chief Executive Officer



                                            /s/ Gail A. Sloan
                                            -----------------------------------
                                            GAIL A. SLOAN
                                            Secretary and Controller