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                                                                    EXHIBIT 10.8


THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE SECURITIES LAWS OF ANY STATE.
THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND
MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE ACT AND THE
APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION
THEREFROM. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN
FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED
TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE
SECURITIES LAWS.

                         QUESTCOR PHARMACEUTICALS, INC.

               WARRANT FOR THE PURCHASE OF SHARES OF COMMON STOCK

April 5, 2001                                                   2,873,563 Shares

For Value Received, QUESTCOR PHARMACEUTICALS, INC., a California corporation
(the "Company"), with its principal office at 26118 Research Road, Hayward,
California 94545, hereby certifies that Sigma-Tau Finance Holding S.A.
("Holder"), or its assigns, in consideration of payment to the Company of
$100,000 and for Holder's purchase of Common Stock pursuant to the Stock and
Warrant Purchase Agreement dated April 5, 2001, by and among the Company and the
Purchaser (the "Purchase Agreement"), is entitled, subject to the provisions of
this Warrant, to purchase from the Company, at any time before 5:00 p.m.
(Pacific Standard Time) on September 29, 2001 (the "Expiration Date"), the
number of fully paid and nonassessable shares of Common Stock of the Company set
forth above, subject to adjustment as hereinafter provided. In the event Holder
exercises this Warrant in full, on or before such Expiration Date, the $100,000
paid for the Warrant will be credited toward the purchase of the aggregate of
2,873,563 shares of Company Common Stock, provided, that if the Company has not
received the shareholder approval contemplated by the last sentence of the
following paragraph, the $100,000 shall be credited toward the purchase of
2,161,752 shares (subject to adjustments for stock-splits, dividends, etc.)

        Holder may purchase such number of shares of Common Stock up to the
number set forth above at an exercise price per share (as appropriately adjusted
pursuant to Section 6 hereof) equal to $0.522 (the "Exercise Price").
Notwithstanding the foregoing, however, Holder shall not exercise this Warrant
for greater than 2,161,752 shares (subject to adjustments for stock-splits,
dividends, etc.), unless the Company has received shareholder approval in
compliance with the rules and regulations of the American Stock Exchange.


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        The term "Common Stock" shall mean the aforementioned Common Stock of
the Company, together with any other equity securities that may be issued by the
Company in addition thereto or in substitution therefor as provided herein. The
number of shares of Common Stock to be received upon the exercise of this
Warrant and the price to be paid for a share of Common Stock are subject to
adjustment from time to time as hereinafter set forth. The shares of Common
Stock deliverable upon such exercise, as adjusted from time to time, are
hereinafter sometimes referred to as "Warrant Shares."

        SECTION 1. EXERCISE OF WARRANT. This Warrant may be exercised in whole
or in part on any business day prior to the Expiration Date by presentation and
surrender hereof to the Company at its principal office at the address set forth
in the initial paragraph hereof (or at such other address as the Company may
hereafter notify Holder in writing) with the Purchase Form annexed hereto duly
executed and accompanied by proper payment of the Exercise Price in lawful money
of the United States of America in the form of a check or wire transfer of
immediately available funds, subject to collection, for the number of Warrant
Shares specified in the Purchase Form. If this Warrant should be exercised in
part only, the Company shall, upon surrender of this Warrant, execute and
deliver a new Warrant evidencing the rights of Holder thereof to purchase the
balance of the Warrant Shares purchasable hereunder. Upon receipt by the Company
of this Warrant and such Purchase Form, together with proper payment of the
Exercise Price, at the principal office of the Company, Holder shall be deemed
to be the holder of record of the Warrant Shares, notwithstanding that the stock
transfer books of the Company shall then be closed or that certificates
representing such Warrant Shares shall not then be actually delivered to Holder.

        SECTION 2. RESERVATION OF SHARES. The Company hereby agrees that at all
times there shall be reserved for issuance and delivery upon exercise of this
Warrant all shares of its Common Stock or other shares of capital stock of the
Company from time to time issuable upon exercise of this Warrant. All such
shares shall be duly authorized and, when issued upon such exercise in
accordance with the terms of this Warrant, shall be validly issued, fully paid
and nonassessable.

        SECTION 3. FRACTIONAL INTEREST. The Company will not issue a fractional
share of Common Stock upon exercise of this Warrant. Instead, the Company will
deliver its check for the current market value of the fractional share. The
current market value of a fraction of a share is determined as follows: multiply
the current market price of a full share by the fraction of a share and round
the result to the nearest cent.

        SECTION 4. TRANSFERS; ASSIGNMENT OR LOSS OF WARRANT.

               (a) Subject to the terms and conditions contained in Section 9
hereof, this Warrant and all rights hereunder are transferable in whole or in
part by Holder and any successor transferee. Notwithstanding the foregoing
sentence, except in the case of a transfer pursuant to Section 4(b), prior to
such transfer Holder shall give thirty (30) days prior written notice of any
such transfer to the Company, and the Company shall have the right to acquire
the Warrant under the identical provisions contained in such notice by giving
Holder written notice within fifteen (15) days of receipt of such notice. The
Company's failure to respond to said notice within said


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fifteen (15) days shall be deemed a waiver of this right of first refusal. The
transfer shall be recorded on the books of the Company upon receipt by the
Company of the Transfer Notice annexed hereto, at its principal offices and the
payment to the Company of all transfer taxes and other governmental charges
imposed on such transfer.

               (b) Without limiting the generality of the first sentence of
clause (a) above, it is understood that Holder and its Affiliates may transfer
the Shares and/or the Warrant to any other Affiliate; provided that such
transfer is in accordance with an exemption from the registration requirements
of the Securities Act. "Affiliate" shall mean (i) any corporation or business
entity 50% or more of the capital or voting stock of which is owned directly or
indirectly by Holder, Claudio Cavazza or Paolo Cavazza; (ii) any corporation or
business entity which directly or indirectly owns 50% or more of the capital or
voting stock of Holder, or (iii) any corporation or business entity under the
direct or indirect control of such corporation or business entity as described
in (i) or (ii) above.

               (c) Subject to the provisions of Section 9, upon surrender of
this Warrant to the Company or at the office of its stock transfer agent or
warrant agent, with the Assignment Form annexed hereto duly executed and funds
sufficient to pay any transfer tax, the Company shall, without charge, execute
and deliver a new Warrant or Warrants in the name of the assignee or assignees
named in such instrument of assignment (any such assignee will then be a
"Holder" for purposes of this Warrant) and, if Holder's entire interest is not
being assigned, in the name of Holder, and this Warrant shall promptly be
canceled.

               (d) Upon receipt of evidence satisfactory to the Company of the
loss, theft, destruction or mutilation of this Warrant, and (in the case of
loss, theft or destruction) of indemnification satisfactory to the Company, and
upon surrender and cancellation of this Warrant, if mutilated, the Company shall
execute and deliver a new Warrant of like tenor and date. In the event that this
Warrant is lost, stolen, destroyed or mutilated, Holder shall pay all reasonable
attorneys' fees and expenses incurred by the Company in connection with the
replacement of this Warrant and the issuance of a new Warrant.

        SECTION 5. RIGHTS OF HOLDER. Holder shall not, by virtue hereof, be
entitled to any rights of a stockholder in the Company, either at law or equity,
and the rights of Holder are limited to those expressed in this Warrant. Nothing
contained in this Warrant shall be construed as conferring upon Holder hereof
the right to vote or to consent or to receive notice as a stockholder of the
Company on any matters or with respect to any rights whatsoever as a stockholder
of the Company. No dividends or interest shall be payable or accrued in respect
of this Warrant or the interest represented hereby or the Warrant Shares
purchasable hereunder until, and only to the extent that, this Warrant shall
have been exercised in accordance with its terms.

        SECTION 6. ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF SHARES. The number
and kind of securities purchasable upon the exercise of the Warrant and the
Exercise Price shall be subject to adjustment from time to time upon the
occurrence of certain events, as follows:


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               (a) RECLASSIFICATION OF OUTSTANDING SECURITIES. In case of any
reclassification, change or conversion of securities of the class issuable upon
exercise of this Warrant (other than a change in par value, or from par value to
no par value, or from no par value to par value, or as a result of a subdivision
or combination), the Company shall execute a new Warrant (in form and substance
reasonably satisfactory to the Holder of this Warrant) providing that the Holder
of this Warrant shall have the right to exercise such new Warrant and upon such
exercise to receive, in lieu of each share of Common Stock theretofore issuable
upon exercise of this Warrant, the kind and amount of shares of stock, other
securities, money and property receivable upon such reclassification or change
by a holder of one share of Common Stock. Such new Warrant shall provide for
adjustments that shall be as nearly equivalent as may be practicable to the
adjustments provided for in this Section 6. The provisions of this subsection
(a) shall similarly apply to successive reclassification or changes.

               (b) SUBDIVISIONS OR COMBINATION OF SHARES. If the Company at any
time while this Warrant remains outstanding and unexpired shall subdivide or
combine its Common Stock, the Exercise Price and the number of Warrant Shares
issuable upon exercise hereof shall be proportionately adjusted.

               (c) STOCK DIVIDENDS. If the Company at any time while this
Warrant is outstanding and unexpired shall pay a dividend payable in shares of
Common Stock (except any distribution specifically provided for in the foregoing
subsections (a) and (b)), then the Exercise Price shall be adjusted, from and
after the date of determination of shareholders entitled to receive such
dividend or distribution, to that price determined by multiplying the Exercise
Price in effect immediately prior to such date of determination by a fraction
(a) the numerator of which shall be the total number of shares of Common Stock
outstanding immediately prior to such dividend or distribution, and (b) the
denominator of which shall be the total number of shares of Common Stock
outstanding immediately after such dividend or distribution, and the number of
Warrant Shares subject to this Warrant shall be proportionately adjusted.

               (d) NOTICE OF RECORD DATE. In the event of any taking by the
Company of a record of its shareholders for the purpose of determining
shareholders who are entitled to receive payment of any dividend (other than a
cash dividend) or other distribution, any right to subscribe for, purchase or
otherwise acquire any share of any class or any other securities or property, or
to receive any other right, or for the purpose of determining shareholders who
are entitled to vote in connection with any proposed merger or consolidation of
the Company with or into any other corporation, or any proposed sale, lease or
conveyance of all or substantially all of the assets of the Company, or any
proposed liquidation, dissolution or winding up of the Company, the Company
shall mail to the Holder of this Warrant, at least ten days prior to the date
specified therein, a notice specifying the date on which any such record is to
be taken for the purpose of such dividend, distribution or right, and the amount
and character of such dividend, distribution or right.

               (e) NO ADJUSTMENT UPON EXERCISE OF WARRANTS. No adjustments shall
be made under any Section herein in connection with the issuance of Warrant
Shares upon exercise of the Warrants.


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        SECTION 7. OFFICER'S CERTIFICATE. Whenever the Exercise Price shall be
adjusted as required by the provisions of Section 6, the Company shall deliver
an officer's certificate showing the adjusted Exercise Price determined as
herein provided, setting forth in reasonable detail the facts requiring such
adjustment and the manner of computing such adjustment. Each such officer's
certificate shall be signed by the chairman, president or chief financial
officer of the Company.

        SECTION 8. TRANSFER TO COMPLY WITH THE SECURITIES ACT OF 1933. This
Warrant may not be exercised and neither this Warrant nor any of the Warrant
Shares, nor any interest in either, may be offered, sold, assigned, pledged,
hypothecated, encumbered or in any other manner transferred or disposed of, in
whole or in part, except in compliance with applicable United States federal and
state securities or blue sky laws and the terms and conditions hereof. Each
Warrant shall bear a legend in substantially the same form as the legend set
forth on the first page of this Warrant. Each certificate for Warrant Shares
issued upon exercise of this Warrant shall bear a legend substantially in the
following form:

        THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
        SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR UNDER THE SECURITIES
        LAWS OF ANY STATE. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON
        TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT
        AS PERMITTED UNDER THE ACT AND THE APPLICABLE STATE SECURITIES LAWS,
        PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. THE ISSUER OF THESE
        SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE
        SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR
        RESALE IS IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE SECURITIES
        LAWS.

Any certificate for any Warrant Shares issued at any time in exchange or
substitution for any certificate for any Warrant Shares bearing such legend
shall also bear such legend unless, in the opinion of counsel for the Company,
the Warrant Shares represented thereby need no longer be subject to the
restriction contained herein. The provisions of this Section 8 shall be binding
upon all subsequent holders of certificates for Warrant Shares bearing the above
legend and all subsequent holders of this Warrant, if any.

        SECTION 9. REPRESENTATIONS AND COVENANTS OF HOLDER. This Warrant has
been entered into by the Company in reliance upon the following representations
and covenants of Holder, which by its execution hereof Holder hereby confirms:

               (a) INVESTMENT PURPOSE. The right to acquire Common Stock, and
any Common Stock issued upon exercise of Holder's rights contained herein, will
be acquired for investment and not with a view to the sale or distribution of
any part thereof, and Holder has no present intention of selling or engaging in
any public distribution of the same except pursuant to a registration or
exemption.


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               (b) PRIVATE ISSUE. Holder understands (i) that the Common Stock
issuable upon exercise of Holder's rights contained herein is not registered
under the Securities Act or qualified under applicable state securities laws on
the ground that the issuance contemplated by this Warrant will be exempt from
the registration and qualification requirements thereof, and (ii) that the
Company's reliance on such exemption is predicated on the representations set
forth in this Section 9.

               (c) FINANCIAL RISK. Holder has such knowledge and experience in
financial and business matters as to be capable of evaluating the merits and
risks of its investment and has the ability to bear the economic risks of its
investment.

               (d) RULE 144. Holder also understands that any sale of its rights
to purchase Common Stock, or of any Common Stock, which might be made by it in
reliance upon Rule 144 under the Securities Act may be made only in accordance
with the terms and conditions of that Rule.

               (e) ACCREDITED INVESTOR. Holder is an "accredited investor"
within the meaning of the Securities Act Rule 501 of Regulation D, as presently
in effect.

        SECTION 10. SATURDAYS, SUNDAYS AND HOLIDAYS. If the last or appointed
day for the taking of any action or the expiration of any right required or
granted herein shall be a Saturday or a Sunday or shall be a legal holiday in
the State of California, then such action may be taken or such right may be
exercised on the next succeeding day not a Saturday, Sunday or legal holiday in
the State of California.

        SECTION 11. ISSUE TAX. The issuance of certificates for Common Stock
upon the exercise of the Warrant shall be made without charge to the holder of
the Warrant for any issue tax (other than any applicable income taxes) in
respect thereof; provided, however, that the Company shall not be required to
pay any tax which may be payable in respect of any transfer involved in the
issuance and delivery of any certificates in a name other than that of the then
Holder of the Warrant being exercised.

        SECTION 12. MODIFICATION AND WAIVER. Neither this Warrant nor any term
hereof may be changed, waived, discharged or terminated other than by an
instrument in writing signed by the Company and by Holder.

        SECTION 13. NOTICES. Unless otherwise specified herein, any notice,
request or other document required or permitted to be given or delivered to
Holder or the Company shall be given in writing and shall be deemed effectively
given (i) upon personal delivery to the party to be notified, (ii) three (3)
days after deposit in the United States mail if sent by registered or certified
mail, postage prepaid, or (iii) one (1) day after deposit with an overnight
courier, specifying next day delivery, with written verification of receipt. All
communications shall be sent to Holder at its address as shown on the books of
the Company, or to the Company at the address indicated therefor in the first
paragraph of this Warrant.


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        SECTION 14. DESCRIPTIVE HEADINGS AND GOVERNING LAW. The description
headings of the several sections and paragraphs of this Warrant are inserted for
convenience only and do not constitute a part of this Warrant. This Warrant
shall be construed and enforced in accordance with, and the rights of the
parties shall be governed by, the laws of the State of California, without
regard to its conflicts of laws principles.

        SECTION 15. ATTORNEYS' FEES. In any litigation, arbitration or court
proceeding between the Company and Holder relating hereto, the prevailing party
shall be entitled to attorneys' fees and expenses and all costs of proceedings
incurred in enforcing this Warrant.

        SECTION 16. SURVIVAL. The representations, warranties, covenants and
conditions of the respective parties contained herein or made pursuant to this
Warrant shall survive the execution and delivery of this Warrant.

        SECTION 17. SEVERABILITY. In the event any one or more of the provisions
of this Warrant shall for any reason be held invalid, illegal or unenforceable,
the remaining provisions of this Warrant shall be unimpaired, and the invalid,
illegal or unenforceable provision shall be replaced by a mutually acceptable
valid, legal and enforceable provision, which comes closest to the intention of
the parties underlying the invalid, illegal or unenforceable provision.

                            [Signature Page Follows]


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        IN WITNESS WHEREOF, the Company has duly caused this Warrant to be
signed by its duly authorized officer and to be dated as of the date first above
written.

                                       COMPANY:

                                       QUESTCOR PHARMACEUTICALS,  INC.

                                       By: /s/ CHARLES J. CASAMENTO
                                           -------------------------------------
                                           Charles J. Casamento
                                           Chief Executive Officer


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                                  PURCHASE FORM

                                                         Dated ___________, ____

        The undersigned hereby irrevocably elects to exercise the within Warrant
to purchase ______ shares of Common Stock and hereby makes payment of
$_____________ in payment of the exercise price thereof, together with all
applicable transfer taxes, if any.

        In exercising its rights to purchase the Common Stock of Questcor
Pharmaceuticals, Inc., the undersigned hereby confirms and acknowledges the
investment representations and warranties made in Section 9 of the Warrant.

        Please issue a certificate or certificates representing said shares of
Common Stock in the name of the undersigned or in such other name as is
specified below.

                                       -----------------------------------------
                                       (Name)

                                       -----------------------------------------
                                       (Address)

                                       -----------------------------------------


                                       HOLDER:

                                       SIGMA-TAU FINANCE HOLDING S.A.

                                       By:
                                          --------------------------------------
                                       Print Name:
                                                   -----------------------------
                                       Title:
                                               ---------------------------------


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                                 ASSIGNMENT FORM

                                                          Dated _________, _____

        FOR VALUE RECEIVED, Sigma-Tau Finance Holding S.A. hereby sells, assigns
and transfers unto _________________________________________________ (the
"Assignee"),           (please type or print in block letters)
________________________________________________________________________________
                                (insert address)
its right to purchase up to __________shares of Common Stock represented by this
Warrant and does hereby irrevocably constitute and appoint _____________________
attorney, to transfer the same on the books of the Company, with full power of
substitution in the premises.

                                       SIGMA-TAU FINANCE HOLDING S.A.

                                       By:
                                          --------------------------------------
                                       Print Name:
                                                   -----------------------------
                                       Title:
                                               ---------------------------------


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                                 TRANSFER NOTICE


        (To transfer or assign the foregoing Warrant, execute this form and
        supply required information. Do not use this form to purchase shares.)

        FOR VALUE RECEIVED, the foregoing Warrant and all rights evidenced
thereby are hereby transferred and assigned to:

--------------------------------------------------------------------------------
                                 (Please Print)

whose address is
                 ---------------------------------------------------------------

--------------------------------------------------------------------------------


                                       Dated
                                             -----------------------------------
                                       Holder's Signature
                                                          ----------------------
                                       Holder's Address
                                                         -----------------------


Note:     The signature to this Transfer Notice must correspond with the name as
          it appears on the face of the Warrant, without alteration or
          enlargement or any change whatever. Officers of corporations and those
          acting in a fiduciary or other representative capacity should file
          proper evidence of authority to assign the foregoing Warrant.


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