AMENDMENT NO. 2 TO
STATEMENT ON SCHEDULE 13D

     This Amendment No. 2 to a Statement on Schedule 13D (this “Amendment No. 2”) amends and supplements the report on Schedule 13D filed with the Securities and Exchange Commission (the “SEC”) on January 26, 2004 (the “Schedule 13D”), as amended by Amendment No. 1 to Schedule 13D filed on February 13, 2004, relating to shares of common stock, no par value (the “Common Stock”), of Questcor Pharmaceuticals, Inc., a California corporation (the “Issuer”). Each item below amends and supplements the information disclosed under the corresponding item of the Schedule 13D. Unless otherwise indicated herein, terms used and defined in this Amendment No. 2 shall have the same respective meanings herein as are ascribed to such terms in the Schedule 13D.

Item 2. Identity and Background.

     The first paragraph of Item 2 of the Schedule 13D is hereby amended and restated in its entirely to read as follows:

     This statement is filed on behalf of: (a) Montreux Equity Partners II SBIC, L.P. (“MEP”), (b) Montreux Equity Management II SBIC, LLC (the “General Partner”), (c) Howard D. Palefsky (“Mr. Palefsky”), and (d) Daniel K. Turner, III (“Mr. Turner”). As described in Item 6 below, MEP may be acting together with (i) Corporate Opportunities Fund, L.P. (“COF”), and (ii) Corporate Opportunities Fund (Institutional), L.P. (“COFI”, and together with COF, the “COF Funds”) for the purpose of voting shares of the Issuer, and therefore may be considered a group within the meaning of Rule 13d-5(b) solely for such purpose. Mr. Albert Hansen is a Manager and Member of SMM Corporate Management, LLC (“COF GP”). COF GP is the sole general partner of the COF Funds.

Item 4. Purpose of Transaction.

     Item 4 of the Schedule 13D is hereby amended to add the following:

     Albert Hansen received proxies from each of Paolo Cavazza, Claudio Cavazza, Defiante Farmaceutica L.D.A. (“Defiante Farma”), and Sigma Tau International S.A. (together with Messrs. Cavazza and Defiante Farma, the “Sigma Tau Group”) dated either May 13, 2004 or May 14, 2004, to vote all shares of Common Stock owned by such persons, which the Reporting Persons believe is an aggregate of 12,425,654 shares of Common Stock, at the 2004 annual meeting of shareholders (the “Annual Meeting”) of the Issuer to be held on May 17, 2004 (collectively, the “Sigma Tau Proxies”). Pursuant to the Sigma Tau Proxies, Mr. Hansen is directed to vote all of the shares of Common Stock held by the Sigma Tau Group at the Annual Meeting as follows:

     In accordance with Article II, Section 12 of the Amended and Restated Bylaws of the Issuer, the Sigma Tau Proxies were duly filed with the Secretary of the Company on May 13, 2004 and May 14, 2004. A copy of the Sigma Tau Proxies are attached hereto as Exhibit 2.

     The Series B Preferred and the Warrants contain certain limitations on the conversion or exercise thereof which make the Series B Preferred inconvertible and the Warrants unexercisable to the extent the holder would, upon conversion or exercise, beneficially own more than 9.9% (the “Restrictive Ownership Threshold”) of the Common Stock, unless the holder notifies the Issuer to increase the Restrictive Ownership Threshold. On February 12, 2004, MEP notified the Issuer to increase the Restrictive Ownership Threshold applicable to the Series B Preferred and Warrants held by MEP from 9.9% to 19.9%. On May 14, 2004, MEP notified the Issuer (the “May Notice”) to increase the Restrictive Ownership Threshold applicable to the Series B Preferred and Warrants held by MEP from 19.9% to 35%. A copy of the May Notice is attached hereto as Exhibit 3 and is incorporated by reference herein.

Item 5. Interest in Securities of the Issuer.

     Item 5 of the Schedule 13D is hereby amended and restated in its entirety to read as follows:

     (a) There are 51,060,220 shares of Common Stock outstanding as of May 7, 2004 (the “Outstanding Shares”), as reported by the Issuer in its quarterly report on Form 10-Q for the period ended March 31, 2004. In addition there are 10,624,731 shares of Common Stock currently issuable upon conversion of all of the outstanding shares of Series B Preferred. Each share of Series B Preferred is currently entitled to a number of votes equal to 0.875 times the number of shares of Common Stock issuable upon conversion of such Series B Preferred, resulting in the total voting equivalence of 9,296,640 shares of Common Stock (the “Converted Shares”). The current voting equivalence of the 2,124,947 aggregate shares of Common Stock (the “MEP Series B Shares”) issuable upon the Series B Preferred currently held by the Reporting Persons is 1,859,329 (the “MEP Converted Shares”). In addition, the Reporting Persons may currently purchase an additional 679,982 shares of Common Stock upon conversion of the Warrants (the “MEP Warrant Shares”).

     By reason of the understanding among MEP and the COF Funds described in Items 4 and 6 herein, MEP and the COF Funds may be deemed to constitute a group under Rule 13d-5(b) for the purpose of voting shares of the Issuer. Based on information set forth in Amendment No. 1 to Schedule 13D filed by the COF Funds on February 13, 2004 (the “COF Schedule 13D”), the COF Funds beneficially own a total of 3,187,420 shares of Common Stock (the “COF Series B Shares”) that are currently issuable upon conversion of 3,000 shares of Series B Preferred. The current voting equivalence of the COF Series B Shares is 2,788,992 (the “COF Converted Shares”). In addition, as reported in the COF Schedule 13D, the COF Funds may currently purchase an additional 1,019,974 shares of Common Stock (the “COF Warrant Shares”) upon conversion of a warrant to purchase shares of Common Stock which they hold. In addition, on May 13, 2004, Sigma Tau Group granted Albert Hansen a proxy to vote an aggregate of 12,425,654 shares of Common Stock owned by the Sigma Tau Group.

     Collectively, the Reporting Persons and the COF Funds, may be deemed to beneficially own a total of (i) 5,312,367 shares of Common Stock (the “Total Series B Shares”) that are currently issuable upon conversion of 5,000 shares of Series B Preferred, (ii) 1,699,956 shares of Common Stock that are currently issuable upon exercise of common stock purchase warrants (the “Total Warrant Shares”), and

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and (iii) 12,425,654 shares of Common Stock owned by the Sigma Tau Group with respect to voting such shares in accordance with the Sigma Tau Proxy at the Annual Meeting (the “Sigma Tau Shares”). The current voting equivalence of the Total Series B Shares is 4,648,321 (the “Total Converted Shares”).

     (i) Holdings if Deemed Members of a Rule 13d-5 Group with the COF Funds.

     If the Reporting Persons are deemed to be members of a group with the COF Funds under Rule 13d-5(b) of the Act, the aggregate number and percentage of shares of Common Stock that may be deemed to be beneficially owned by each Reporting Person pursuant to Rule 13d-3 of the Act is as follows:

     (ii) Holdings if Not Deemed Members of a Rule 13d-5 Group with the COF Funds.

     If the Reporting Persons are not deemed to be members of a group with the COF Funds under Rule 13d-5(b) of the Act, the aggregate number and percentage of shares of Common Stock that may be deemed to be beneficially owned by each Reporting Person pursuant to Rule 13d-3 of the Act is as follows:

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     (b) (i) Holdings if Deemed Members of a Rule 13d-5 Group with the COF Funds.

     If the Reporting Persons are deemed to be members of a group with the COF Funds under Rule 13d-5(b) of the Act, the number of shares of Common Stock as to which there is sole power to direct the vote, shared power to vote or to direct the vote, sole power to dispose or direct the disposition, or shared power to dispose or direct the disposition for each of the Reporting Persons is as follows:

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     (ii) Holdings if Not Deemed Members of a Rule 13d-5 Group with the COF Funds.

     If the Reporting Persons are not deemed to be members of a group with the COF Funds under Rule 13d-5(b) of the Act, the number of shares of Common Stock as to which there is sole power to direct the vote, shared power to vote or to direct the vote, sole power to dispose or direct the disposition, or shared power to dispose or direct the disposition for each of the Reporting Persons is as follows:

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

     Item 6 of the Schedule 13D is hereby amended to add the following:

     Albert Hansen received proxies from each of Paolo Cavazza, Claudio Cavazza, Defiante Farma, and Sigma Tau International S.A. (together with Messrs. Cavazza and Defiante Farma, the “Sigma Tau Group”) dated either May 13, 2004 or May 14, 2004, to vote all shares of Common Stock owned by such persons, which the Reporting Persons believe is an aggregate of 12,425,654 shares of Common Stock, at the 2004 annual meeting of shareholders (the “Annual Meeting”) of the Issuer to be held on May 17, 2004 (collectively, the “Sigma Tau Proxies”). Pursuant to the Sigma Tau Proxies, Mr. Hansen is directed to vote all of the shares of Common Stock held by the Sigma Tau Group at the Annual Meeting as follows:

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     In accordance with Article II, Section 12 of the Amended and Restated Bylaws of the Issuer, the Sigma Tau Proxies were duly filed with the Secretary of the Company on May 13, 2004 and May 14, 2004. A copy of the Sigma Tau Proxies are attached hereto as Exhibit 2.

     The Series B Preferred and the Warrants contain certain limitations on the conversion or exercise thereof which make the Series B Preferred inconvertible and the Warrants unexercisable to the extent the holder would, upon conversion or exercise, beneficially own more than 9.9% (the “Restrictive Ownership Threshold”) of the Common Stock, unless the holder notifies the Issuer to increase the Restrictive Ownership Threshold. On February 12, 2004, MEP notified the Issuer to increase the Restrictive Ownership Threshold applicable to the Series B Preferred and Warrants held by MEP from 9.9% to 19.9%. On May 14, 2004, MEP notified the Issuer (the “May Notice”) to increase the Restrictive Ownership Threshold applicable to the Series B Preferred and Warrants held by MEP from 19.9% to 35%. A copy of the May Notice is attached hereto as Exhibit 3 and is incorporated by reference herein.

     Except as stated in this Item 6 or elsewhere in the Schedule 13D, to the best knowledge of each Reporting Person, no Reporting Person is a party to any contract, arrangement, understanding, or relationship (legal or otherwise) with any person with respect to any securities of the Issuer, including but not limited to, any transfer or voting of any such securities, finder’s fees, joint ventures, loans or option arrangements, puts or calls, guarantees or profits, divisions of profit or loss, or the giving or withholding of proxies.

Item 7. Material to be Filed as Exhibits.

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SCHEDULE 13D

SIGNATURES

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement with respect to Montreux Equity Partners II SBIC, L.P. is true, complete and correct.

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement with respect to Montreux Equity Management II SBIC, LLC is true, complete and correct.

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement with respect to Howard D. Palefsky is true, complete and correct.

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement with respect to Daniel K. Turner, III is true, complete and correct.

Attention: Intentional misstatements or omissions of fact constitute Federal criminal violations
(See 18 U.S.C. 1001)

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EXHIBIT 1

JOINT FILING AGREEMENT

     The undersigned hereby agree that the statement on Schedule 13D with respect to the Common Stock of Questcor Pharmaceuticals, Inc., dated as of May 14, 2004 is, and any amendments thereto signed by each of the undersigned and shall be, filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934.

     This joint filing agreement may be executed in counterparts, each of which shall for all purposes be deemed to be an original and all of which shall constitute one and the same instrument.

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EXHIBIT 2

SIGMA TAU PROXIES

EXHIBIT 3

MONTREUX EQUITY PARTNERS II SBIC, L.P.
2500 SAND HILL ROAD
SUITE 215
MENLO PARK, CA 94025

May 14, 2004

via Fedex and Facsimile (510) 400-0715

Gentlemen:

     Pursuant to Section 10(g)(1) of the Certificate of Determination of Series B Convertible Preferred Stock (the “Certificate”) of Questcor Pharmaceuticals, Inc., a California corporation (the “Company”), and pursuant to Section 2(c)(1) of the Common Stock Purchase Warrant, dated as of January 15, 2003 (the “Warrant”), to purchase shares of Common Stock of the Company held by Montreux Equity Partners II SBIC, L.P., a California limited partnership (the “Holder”), the Holder hereby notifies you, effective as of the date hereof, that the Holder:

     (i) has increased its Restricted Ownership Percentage (as defined in the Certificate) of the Holder from 19.9% to 35.0%; and

     (ii) has increased the Restricted Ownership Percentage (as defined in the Warrant) of the Holder from 19.9% to 35.0%.

     The Holder reserves its right to further increase or to decrease its Restricted Ownership Percentage from time to time in accordance with the Certificate and the Warrant. Please confirm and acknowledge receipt of this notice by executing the attached Confirmation and returning it to the undersigned in the enclosed return Fedex envelope.