U.S. SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                     FORM 4

                  STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

    Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934,
       Section 17(a) of the Public Utility Holding Company Act of 1935 or
               Section 30(f) of the Investment Company Act of 1940

[_]  Check box if no longer  subject to Section 16. Form 4 or Form 5 obligations
     may continue. See Instruction 1(b).

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1.   Name and Address of Reporting Person*

     Sigma Tau Finance International S.A. (f/k/a Sigma Tau Finance Holding S.A.)
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   (Last)                           (First)             (Middle)

     Avenue Pasteur, 6
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                                    (Street)

     Luxembourg                   Luxembourg            LP-2310
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   (City)                           (State)              (Zip)


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2.   Issuer Name and Ticker or Trading Symbol


     Questcor Pharmaceuticals, Inc. (QSC)
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3.   IRS Identification Number of Reporting Person, if an Entity (Voluntary)



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4.   Statement for Month/Year


     03/2002
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5.   If Amendment, Date of Original (Month/Year)


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6.   Relationship of Reporting Person to Issuer
     (Check all applicable)

     [_]  Director                             [X]  10% Owner
     [_]  Officer (give title below)           [_]  Other (specify below)


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7.   Individual or Joint/Group Filing (Check applicable line)

     [X]  Form filed by one Reporting Person
     [_]  Form filed by more than one Reporting Person
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           Table I -- Non-Derivative Securities Acquired, Disposed of,
                             or Beneficially Owned
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6. 4. 5. Owner- Securities Acquired (A) or Amount of ship 3. Disposed of (D) Securities Form: 7. Transaction (Instr. 3, 4 and 5) Beneficially Direct Nature of 2. Code ------------------------------- Owned at End (D) or Indirect 1. Transaction (Instr. 8) (A) of Month Indirect Beneficial Title of Security Date ------------ Amount or Price (Instr. 3 (I) Ownership (Instr. 3) (mm/dd/yy) Code V (D) and 4) (Instr.4) (Instr. 4) - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/14/02 P 5,000 A $1.6374 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/15/02 P 5,000 A $1.7450 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/18/02 P 5,000 A $1.8642 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/19/02 P 10,000 A $1.8492 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/20/02 P 10,000 A $1.8156 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/21/02 P 10,000 A $1.8200 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/22/02 P 10,000 A $1.8230 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/25/02 P 10,000 A $1.7912 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/26/02 P 10,000 A $1.8455 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/27/02 P 10,000 A $1.8393 D - ------------------------------------------------------------------------------------------------------------------------------------ Common Stock 3/28/02 P 10,000 A $1.9439 8,267,597 D ====================================================================================================================================
* If the Form is filed by more than one Reporting Person, see Instruction 4(b)(v). Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. (Print or Type Response) (Over) FORM 4 (continued) Table II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities) ================================================================================
10. 9. Owner- Number ship of Form 2. Deriv- of Conver- 5. 7. ative Deriv- 11. sion Number of Title and Amount Secur- ative Nature or Derivative 6. of Underlying 8. ities Secur- of Exer- 4. Securities Date Securities Price Bene- ity: In- cise 3. Trans- Acquired (A) Exercisable and (Instr. 3 and 4) of ficially Direct direct Price Trans- action or Disposed Expiration Date ---------------- Deriv- Owned (D) or Bene- 1. of action Code of(D) (Month/Day/Year) Amount ative at End In- ficial Title of Deriv- Date (Instr. (Instr. 3, ---------------- or Secur- of direct Owner- Derivative ative (Month/ 8) 4 and 5) Date Expira- Number ity Month (I) ship Security Secur- Day/ ------ ------------ Exer- tion of (Instr. (Instr. (Instr. (Instr. (Instr. 3) ity Year) Code V (A) (D) cisable Date Title Shares 5) 4) 4) 4) - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ - ------------------------------------------------------------------------------------------------------------------------------------ ====================================================================================================================================
Explanation of Responses: (1) Shares solely owned by Sigma-Tau Finance International S.A. (f/k/a Sigma Tau Finance Holding S.A.) a wholly owned subsidiary of Sigma-Tau Finanziaria SpA. Mr. Cavazza owns 60% of Sigma-Tau Finanziaria SpA. (2) The 8% Convertible Debenture due 2005 and the Common Stock Warrant were both purchased pursuant to a Securities Purchase Agreement dated March 15, 2002 for a combined purchase price of $2,000,000. (3) Security solely owned by Defiante Farmaceutica Uniperssoal L.D.A., a wholly owned subsidiary of Sigma-Tau Finanziaria SpA. Mr. Cavazza owns 60% of Sigma-Tau Finanziaria SpA. /s/ Antonio Nicolai April 9, 2002 - --------------------------------------------- ----------------------- **Signature of Reporting Person Date ** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a). Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedure. Page 2