<PAGE>

                                                                   EXHIBIT 10.33

                              SEPARATION AGREEMENT

      This SEPARATION AGREEMENT (this "Agreement") is entered into by and
between Questcor Pharmaceuticals, Inc., a California corporation (the "Company")
and Charles J. Casamento (the "Executive"). The Company and the Executive are
sometimes referred to herein as a "Party" or collectively as the "Parties."

      WHEREAS, Executive has been employed by the Company as President and Chief
Executive Officer pursuant to an Employment Agreement dated as of August 4,
1999, as amended to date (the "Employment Agreement"); and

      WHEREAS, Executive and the Company wish to terminate their employment
relationship effective as of the Effective Date (defined below), to characterize
that termination as a resignation, and to resolve all of their obligations to
each other, including, without limitation, under the Employment Agreement.

      NOW, THEREFORE, in consideration of the mutual covenants contained in this
Agreement, and for other good and valuable consideration, the adequacy of which
is hereby acknowledged, the Parties hereby agree as follows:

      1.    Effective Date. This Agreement shall become effective upon the
execution of the Agreement by the Parties in accordance with paragraph 20(f) of
this Agreement. The date on which the later of the Parties to sign has executed
the Agreement shall be referred to in this Agreement as the Effective Date.

      2.    Employment Agreement. The Employment Agreement shall be superseded
entirely by this Agreement, and the Employment Agreement shall be of no further
force or effect.

      3.    Employment and Officer Status. Executive's employment by the Company
shall terminate effective as of the Effective Date. Executive's termination
shall be reflected in the Company's records as a voluntary resignation for
professional reasons. Executive hereby resigns from his position as President
and Chief Executive Officer (and any other officer positions he may hold) of the
Company (and any of its affiliates and subsidiaries) effective as of the
Effective Date. Executive shall execute any additional documentation necessary
to effectuate such resignations.

      4.    Resignation From Board. Executive hereby resigns from his position
as a member of the Company's Board of Directors. Executive shall execute any
additional documentation necessary to effectuate such resignation.

      5.    Compensation After the Effective Date. Within ten (10) days after
the Effective Date, the Company shall issue Executive his final paycheck,
reflecting (a) his earned but unpaid base salary through the Effective Date and
(b) all accrued, unused vacation due Executive through the Effective Date. The
Company, within forty five (45) days after the

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<PAGE>

Effective Date, will reimburse Executive for any and all reasonable and
necessary business expenses incurred by Executive in connection with the
performance of his job duties, which expenses shall be submitted to the Company
with supporting receipts and/or documentation no later than forty (40) days
after the Effective Date. Within ten (10) days after the Effective Date, the
Company shall also issue to Executive a check in the amount of $136,294 (one
hundred thirty six thousand two hundred ninety four dollars), representing
Executive's maximum bonus opportunity for 2004 pro rated through the Effective
Date. From the Effective Date through the eighteen month anniversary of the
Effective Date (i.e., an eighteen month period), the Company shall continue to
pay Executive his regular monthly base salary in the amount of $38,208.33
(thirty eight thousand two hundred eight and thirty-three cents), to be paid on
a twice per month basis in accordance with the Company's payroll practices. The
payments described in this paragraph shall be subject to all applicable taxes
and withholding. Executive acknowledges and agrees that the payments and
benefits described in this paragraph and elsewhere in this Agreement constitute
the only compensation, benefits, or other amounts to which he is entitled
pursuant to the Employment Agreement or any policies, practices, or benefit
programs maintained by the Company related to compensation and benefits. Any
payment made to Executive in accordance with this paragraph shall be made only
to the extent the release set forth in paragraph 10 becomes irrevocable in
accordance with paragraph 10(f).

      6.    Consulting Arrangement. For a period of six (6) months following the
Effective Date (the "Consulting Period"), Executive shall be available to
provide consulting services to the Company, if and as requested by the Board of
Directors of the Company. The Company shall pay Executive as an independent
contractor at the rate of $250 per hour for such consulting services performed
and approved in advance and shall reimburse Executive for reasonable
out-of-pocket expenses, approved in advance, actually incurred by Executive and
supported by adequate documentation. During the Consulting Period, Executive
shall make himself available as reasonably scheduled by the parties for such
consultation and assistance associated with providing transition assistance as
the Board of Directors reasonably may request from time to time, not to exceed
ten (10) hours per month for the first three months and five (5) hours per month
for the next three months; provided, however, that (a) Executive shall not be
required to travel in connection with such services; and (b) it is acknowledged
and agreed that any such services must be scheduled after giving due regard to
Executive's other business and personal commitments (which commitments may
include full time employment). Executive shall have no authority to bind the
Company. Executive's maximum cumulative liability with respect to any and all
breaches of this paragraph 6 shall not exceed $15,000.

      7.    Benefits On and After the Effective Date; Status of Stock Options.

            (a)   Executive acknowledges and agrees that, except to the extent
he is eligible to continue his medical and dental benefits at his sole expense
pursuant to COBRA, and timely elects to do so, his entitlement to benefits and
eligibility to participate in the Company's benefit plans shall cease on the
Effective Date; provided, however, that Executive shall be entitled to those
benefits available to a terminated employee under the Company's 401(k) plan,
life insurance plan and disability plan, to the extent such benefits were
acquired by Executive prior to the Effective Date.

            (b)   The Company acknowledges and agrees that with respect to
129,251 of the New Options (as defined in the Employment Agreement) that have
not vested as of the Effective Date, such options shall become fully vested on
November 18, 2004 and will

                                       2
<PAGE>

remain exercisable by Executive for a period of eighteen (18) months following
the Effective Date. The Company acknowledges and agrees that with respect to the
remaining portion of the New Options that have vested as of the Effective Date,
such options are fully vested and will remain exercisable by Executive for a
period of ninety (90) days following the Effective Date.

      8.    General Release of Claims.

            (a)   Executive, on behalf of himself and his heirs, executors,
administrators, successors, agents, and assigns, hereby fully and without
limitation (except as expressly provided herein) releases and forever discharges
the Company and (as the case may be) its present and former shareholders,
parents, owners, members, subsidiaries, divisions, affiliates, officers,
directors, agents, employees, consultants, insurers, representatives, lawyers,
predecessors, successors and assigns, employee welfare benefit plans and pension
or deferred compensation plans under Section 401 of the Internal Revenue Code of
1986, as amended, and their trustees, administrators and other fiduciaries, and
all persons acting by, through, under or in concert with them, or any of them
("Company Releasees"), both individually and collectively, from any and all
rights, claims, demands, liabilities, actions, causes of action, damages,
losses, costs, expenses and compensation, of whatever nature whatsoever, known
or unknown, fixed or contingent ("Claims"), which Executive may have, or now
claim to have against, or in the future claim from the Releasees by reason of
any matter, cause, or thing whatsoever, from the beginning of time to the date
hereof, in any way related to the Company or its business, including, without
limiting the generality of the foregoing, any Claims arising out of, based upon,
or relating to Executive's recruitment, relocation, hire, employment, benefits,
remuneration (including salary; bonus; incentive or other compensation;
vacation, sick leave or medical insurance benefits; and/or benefits from any
employee stock ownership, profit-sharing and/or any deferred compensation plan
under Section 401 of the Internal Revenue Code of 1986, as amended) or
termination by the Company, or any contract, agreement, or compensation
arrangement between Executive and the Company (including without limitation the
Employment Agreement). As part of this release, Executive expressly waives any
Claims arising out of Title VII of the Civil Rights Act of 1964, as amended; the
Equal Pay Act, as amended; the Age Discrimination in Employment Act, as amended;
the Family and Medical Leave Act of 1993; the California Fair Employment and
Housing Act of 1993, as amended; the California Labor Code (including but not
limited to Section 970); the Fair Labor Standards Act, as amended; Section 17200
of the Business and Professions Code; the federal and state wage and hour laws;
the Americans With Disabilities Act, as amended; the Immigration Reform and
Control Act of 1986; the Executive Retirement Income Security Act of 1974, as
amended; the Uniformed Services Employment and Reemployment Rights Act; the
Rehabilitation Act of 1973, as amended; the California Family Rights Act; the
Worker Adjustment and Retraining Notification Act; the common law of fraud,
misrepresentation, negligence, defamation, infliction of emotional distress,
breach of contract, or wrongful termination; and/or any other local, state or
federal law, rule, or regulation governing employment, discrimination in
employment or the payment of wages and benefits (collectively, the "Specified
Areas"). Executive understands and agrees that he is giving up his status as an
employee and has no rights to be recalled, rehired, or reinstated by the
Company. The forgoing release shall not affect Executive's ownership of capital
stock of the Company or rights under stock options of the Company. Excluded from
the foregoing release are any rights of Executive to indemnity (and payment of
expenses) under the provisions of the Company's Articles of Incorporation and
Bylaws, under the provisions of Section 8.2 of the Employment Agreement (which
provision shall survive the Effective Date, notwithstanding

                                       3
<PAGE>

any other provision hereof), under the Indemnification Agreement between the
Executive and the Company, or pursuant to applicable law. The Company hereby
agrees to provide indemnification to Executive on the same basis that it
provides indemnification to continuing Company officers.

            (b)   The Company, on behalf of itself and the other Company
Releasees hereby fully and without limitation (except as expressly provided
herein) releases and forever discharges Executive, his heirs, executors,
administrators, successors, agents, lawyers and assigns ("Executive Releasees"),
both individually and collectively, from any and all Claims which Executive may
have, or now claim to have against, or in the future claim from the Executive
Releasees by reason of any matter, cause, or thing whatsoever, from the
beginning of time to the date hereof, in any way related to the Company or its
business, including, without limiting the generality of the foregoing, any
Claims in the Specified Areas. Excluded from the foregoing release is any
conduct of Executive constituting fraud, breach of fiduciary duty, dishonesty or
a violation of applicable law. Notwithstanding the forgoing, the Company
represents that it has no current actual knowledge of any conduct of Executive
constituting fraud, breach of fiduciary duty, dishonesty or a violation of
applicable law.

      9.    Waiver of Unknown Claims. Each Party is aware of California Civil
Code Section 1542, which provides as follows:

      A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT
      KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME OF EXECUTING THE
      RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY AFFECTED HIS
      SETTLEMENT WITH THE DEBTOR.

      With full awareness and understanding of the above provisions, each Party
hereby waives any rights he may have under Section 1542, as well as under any
other statutes or common law principles of similar effect. Each Party intends
to, and hereby does, release the relevant releasees from claims which such Party
does not presently know or suspect to exist at this time.

      10.   Release of Age Discrimination Claims. Executive expressly waives and
releases all claims that Executive has or may have under the Age Discrimination
in Employment Act of 1967, as amended, 29 U.S.C. Section 621, et seq. ("ADEA").
The following terms and conditions apply to and are part of the waiver and
release of the ADEA claims under this Agreement:

            a.    That this section and this Agreement are written in a manner
calculated to be understood by Executive.

            b.    The waiver and release of claims under the ADEA contained in
this Agreement do not cover rights or claims that may arise after the date on
which Executive signs this Agreement.

            c.    This Agreement provides for consideration in addition to
anything of value to which Executive is already entitled.

                                       4
<PAGE>

            d.    Executive is advised to consult an attorney before signing
this Agreement.

            e.    Executive is granted twenty-one (21) days after Executive is
presented with this Agreement to decide whether or not to sign this Agreement.
If Executive executes this Agreement prior to the expiration of such period,
Executive does so voluntarily and after having had the opportunity to consult
with an attorney.

            f.    Executive may revoke this Agreement within seven (7) days of
execution of the Agreement by Executive. Unless revoked by Executive, this
release shall become irrevocable upon the expiration of such 7-day period. In
the event of such a revocation, Executive shall not be entitled to the
consideration for this release set forth in paragraph 5 and 6.

      11.   No Admission. Executive further understands and agrees that neither
the payment of money nor the execution of this Agreement shall constitute or be
construed as an admission of any liability whatsoever by the Company Releasees
or Executive Releasees.

      12.   No Lawsuits; No Assignment of Claims. Each Party represents that he
or it knows of no lawsuits pending by such Party against any one or more of the
relevant releasees. Each Party agrees if there are any such lawsuits to dismiss
any and all lawsuits that such Party might have filed against the relevant
releasees to the extent released hereby. Each Party promises never to file or
prosecute a lawsuit asserting any Claims against any of the relevant releasees
or, except as otherwise required by applicable law or legal process, directly or
indirectly assist any other person in so doing, to the extent released hereby.
Each Party represents and warrants to the relevant releasees that there has been
no assignment or other transfer of any interest in any Claim which such Party
may have against the relevant releasees, and such Party agrees to indemnify and
hold the relevant releasees harmless from any liability, claims, demands,
damages, costs, expenses and attorneys' fees incurred as a result of any person
asserting any such assignment or transfer of any rights or Claims under any such
assignment or transfer from such Party.

      13.   Proprietary Information. The Executive acknowledges that certain
information, observations and data obtained by him during the course of or
related to his employment with the Company (including, without limitation,
information with respect to the Company's and its affiliates' operations,
processes, products, inventions, business practices, finances, principals,
vendors, suppliers, customers, potential customers, shareholders, business
plans, marketing plans, proposals or methods, costs, prices, contractual
relationships, regulatory status, compensation paid to employees or other terms
of employment) are the sole property of the Company and constitute trade secrets
of the Company. Promptly following the Effective Date, the Executive agrees to
return all files, customer lists, financial information or other Company
property (excluding documents that have been publicly filed with the SEC) which
are in the Executive's possession or control without making copies thereof.
Except as required pursuant to applicable law, the Executive further agrees that
he will not disclose to any person or use for his own account any of the above
described trade secret information, observations or data without the written
consent of the Company's Board of Directors. Further, the Executive acknowledges
that any unauthorized use of the above described confidential information will
cause irreparable harm to the Company and will give rise to an immediate action
by the Company for injunctive relief. Notwithstanding the above, the Company
acknowledges that Executive may retain and use his own personal address list of
his personal contacts accumulated

                                       5
<PAGE>

over his career (including as accumulated during his employment with the
Company).

      14.   Cooperation Clause. Executive agrees to cooperate fully with the
Company (including its Board of Directors and any special committees of the
Board of Directors) and its counsel or accountants in any financial audits or
internal investigation involving securities, financial or accounting matters,
and in its defense of, or other participation in, any administrative, judicial,
or other proceeding arising from any charge, complaint or other action which has
been or may be filed relating to the period during which Executive was employed
by the Company. The Company agrees to reimburse Executive for his reasonable and
actual expenses incurred in providing such cooperation.

      15.   Indemnity. Executive will continue to be indemnified by any
applicable insurance policies, pursuant to the Articles of Incorporation and
bylaws of the Company, under the provisions of Section 8.2 of the Employment
Agreement (which provision shall survive the Effective Date, notwithstanding any
other provision hereof), the Indemnification Agreement between the Executive and
the Company, and as otherwise required by law for his actions as an employee,
officer or director prior to the Effective Date to the same extent as during his
employment to the fullest extent provided by law.

      16.   Confidentiality of Agreement. Except as expressly set forth in
paragraph 17, the provisions of this Agreement shall be held in strictest
confidence by Executive and the Company and shall not be publicized or disclosed
in any manner whatsoever; provided, however, that: (a) Executive may disclose
this Agreement, in confidence, to his immediate family; (b) the Parties may
disclose this Agreement in confidence to their respective attorneys,
accountants, auditors, tax preparers, and financial advisors; (c) the Company
may disclose this Agreement as necessary to fulfill standard or legally required
corporate reporting or disclosure requirements; and (d) the Parties may disclose
this Agreement insofar as such disclosure may be necessary to enforce its terms
or as otherwise required by law; and (e) Executive may inform third parties that
he voluntarily resigned from the Company on good terms, that he was a valued
employee in good standing with the Company at all times while employed and at
the time of departure and that the Company retained him as a consultant to the
Company immediately following such departure. The Company will make only
statements consistent with the foregoing.

      17.   Press Release; Mutual Nondisparagement. The Company shall issue a
press release regarding Executive's resignation in the form attached hereto as
Exhibit A. Except as required by law or court order, neither the Company nor
Executive shall make any additional or inconsistent public statement regarding
Executive's resignation. Each party to this Agreement promises not to disparage
or otherwise publish or communicate derogatory statements or opinions about the
other to any third party.

      18.   Non-Competition. Executive shall not at any time during the period
during which payments are made by the Company to Executive pursuant to paragraph
5 hereof (the "Non-Compete Period"):


            a.    Either directly or indirectly, or solely or jointly with other
persons or entities, own, manage, operate, join, control, consult with, render
services for or participate in the ownership, management, operation or control
of, or be connected as an officer, director, employee, partner, principal,
agent, consultant or other representative with, or permit his name to be used in
connection with, any profit or non-profit business, organization or entity
(other than

                                       6
<PAGE>

the Company and its affiliates) which operates or engages in or owns an interest
in a Competing Business (defined below);

            b.    Lend any credit or money for the purposes of establishing or
operating any Competing Business, or otherwise give aid or advice to any person,
firm, association, corporation or entity engaging in any Competing Business; or

            c.    Solicit, contact, divert or take away or attempt to solicit,
divert or take away any of the customers, potential customers, business or
patrons of the Company and its affiliates (or any of their respective successors
and assigns), directly or indirectly, by or for himself, or as the agent of any
other person or entity, or through others as an agent or on behalf of a
Competing Business.

            d.    Notwithstanding the foregoing, Executive may own publicly
traded securities issued by a Competing Business, provided that Executive shall
not own more than one percent (1%) of the value of any class of such securities
outstanding at such time.

            e.    A "Competing Business" as used in the Agreement shall refer to
any person or entity engaged in the business of selling pharmaceutical products
for the treatment of seizure disorders, multiple sclerosis, Crohn's disease,
colitis and/or inflammatory bowel disease. The restrictions contained in clauses
(a) through (c) above shall apply only to Executive's actions within the cities,
counties, states of the United States and other countries where the Company and
its affiliates do business during the Non-Compete Period. The Company and
Executive acknowledge and agree that the duration, scope and geographic area for
which this covenant is to be effective are reasonable.

            f.    The Company and Executive intend that the provisions of this
paragraph 18 shall be fully enforceable as set forth herein. To the extent that
any court of competent jurisdiction finds that any such provision is
unenforceable by reason of its duration or scope, the Company and Executive
agree that it shall be enforced insofar as it may be enforced within the limits
of the law of that jurisdiction, but that the Agreement as a whole shall be
unaffected elsewhere.

            g.    The Company and Executive recognize and acknowledge that the
Company, by the Agreement, has sought to prohibit competition by Executive
during the Non-Compete Period, and that Executive's performance of services in
contravention of the Agreement or other breach of the provisions of this
paragraph 18 would consequently cause immediate and irreparable harm to the
business and goodwill of the Company and its affiliates, the exact amount of
which will be difficult or impossible to ascertain, and that damages, if any,
and other remedies at law would be inadequate. Accordingly, should Executive
perform, or attempt or threaten to perform, services in contravention of the
Agreement or otherwise breach the provisions of this paragraph 18, the Company
shall, in addition to any and all other remedies available to it under the
Agreement, have the right to seek and obtain an injunction or other equitable
relief, restraining and preventing Executive from performing such services or
breaching the provisions of this paragraph 18.

            h.    If Executive breaches any provision of this paragraph 18, the
rights of Executive (or Executive's estate) to a benefit under paragraph 5 of
this Agreement shall be

                                       7
<PAGE>

forfeited, unless the Company determines that such activity is not detrimental
to the best interests of the Company and its affiliates. Such forfeiture shall
be in addition to any other remedy of the Company under the Agreement or at law
and in equity with respect to such breach. However, if Executive ceases such
activity and notifies the Company of this action, Executive's (or Executive's
estate's) right to receive a benefit, and any right of a surviving spouse of
Executive or any other person to a benefit, may be restored within 60 days of
said notification, unless the Company in its reasonable discretion determines
that the prior activity has caused serious injury to the Company and its
affiliates.

      19.   Solicitation of Employees. Executive shall not, at any time during
the Non-Compete Period, directly or indirectly, by or for himself, or as the
agent of any other person or entity, or through others as an agent, in any way
solicit or induce, or attempt to solicit or induce, any employee, officer,
representative, consultant, or other agent of the Company or its affiliates,
whether such person is presently employed with the Company or an affiliate or
may hereinafter be so employed, to leave the Company's employ or the employ of a
Company affiliate or otherwise interfere with the employment relationship
between any such person and the Company and its affiliates.

      20.   Miscellaneous Provisions.

            a.    The provisions of this Agreement are severable. If any
provision is held to be invalid or unenforceable it shall not affect the
validity or enforceability of any other provision.

            b.    This Agreement represents the sole and entire agreement
between the Parties with respect to the subject matters contained herein and
supersede all prior documents, agreements, negotiations and discussions between
the Parties with respect to the subject matters contained herein.

            c.    No provision of this Agreement may be altered, modified or
amended unless such alteration, modification, or amendment is agreed to in
writing and signed by Executive on the one hand and the Company on the other,
which writing expressly states the intent of the Parties to modify this
Agreement.

            d.    This Agreement shall be construed as a whole in accordance
with its fair meaning and in accordance with the laws of the State of
California. The language in the Agreement shall not be construed for or against
any particular Party. The headings used herein are for reference only and shall
not affect the construction of this Agreement.

            e.    No waiver by any Party hereto at any time of any breach of, or
compliance with, any condition or provision of this Agreement to be performed by
any other Party hereto shall be deemed a waiver of similar or dissimilar
provisions or conditions at the same or at any prior or subsequent time.

            f.    This Agreement may be executed in one or more counterparts,
and by facsimile, each of which shall be deemed to be an original as against any
Party that has signed it, but all of which together will constitute one and the
same instrument.

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<PAGE>

            g.    If any Party to this Agreement brings an action to enforce his
or its rights hereunder, the prevailing party shall be entitled to recover his
or its costs and expenses, including court costs and attorneys' fees, if any,
incurred in connection with such suit.

            h.    Executive acknowledges that the severance payment provided in
this Release has tax consequences, that the Company has not provided any tax
advice, and that Executive is free to consult with an accountant, legal counsel,
or other tax advisor regarding the tax consequences he may face.

            i.    EACH PARTY ACKNOWLEDGES THAT HE HAS READ THIS AGREEMENT
CAREFULLY, UNDERSTANDS ALL OF ITS TERMS, AND AGREES TO THOSE TERMS KNOWINGLY,
FREELY, VOLUNTARILY, AND WITHOUT DURESS. EACH PARTY ACKNOWLEDGES AND UNDERSTANDS
THAT THIS AGREEMENT INCLUDES A GENERAL RELEASE OF ALL KNOWN AND UNKNOWN CLAIMS.

                            [Signature Page Follows]

                                       9
<PAGE>

            IN WITNESS WHEREOF, the Parties hereto have executed this Agreement
on the dates indicated below.

EXECUTIVE                                         QUESTCOR PHARMACEUTICALS, INC.

/s/ CHARLES J. CASAMENTO                          By: /s/ TIMOTHY E. MORRIS
------------------------                              ---------------------
Charles J. Casamento                                   Timothy E. Morris
                                                  Its: Chief Financial Officer

Dated:  August 5, 2004                            Dated:  August 5, 2004

                                       10
<PAGE>

                                    EXHIBIT A

FOR IMMEDIATE RELEASE

COMPANY CONTACT:
Questcor Pharmaceuticals, Inc.
Timothy E. Morris, Sr. Vice President
Finance & Administration, Chief Financial Officer
and member of the Office of the President
510/400-0700

         QUESTCOR ANNOUNCES RESIGNATION OF PRESIDENT AND CEO CHARLES J.
                                   CASAMENTO


UNION CITY, CA - AUGUST 6, 2004 -- QUESTCOR PHARMACEUTICALS, INC. (AMEX: QSC), a
specialty pharmaceutical company that acquires, markets and sells brand name
prescription drugs for gastrointestinal and neurological use through a U.S.
direct sales force and international distributors, announced today that Charles
J. Casamento has resigned as President and CEO of the Company. Mr. Casamento
also has resigned from the Board of Directors. However, he will continue to act
as a consultant to the Company. The Board of Directors will be working to
identify a successor. In the interim, Timothy E. Morris, CFO, and R. Jerald
Beers, Vice President of Sales and Marketing, will form an Office of the
President to guide the Company along with the Board's continuing oversight.

Mr. Casamento served as President, CEO and a member of the Board of Directors of
the Company since 1999. "I am excited about the future of Questcor and very
comfortable that the Company will be in the capable hands of the corporate
officers and the Board of Directors," noted Mr. Casamento. He added, "My years
with Questcor have been some of the most interesting and rewarding of my 30
years in the pharmaceutical industry and I am proud to have had a role in
building a unique and promising company."

Neal Bradsher, Questcor's Lead Director stated, "Mr. Casamento has contributed
greatly to Questcor's emergence as a specialty pharmaceutical company with
several marketed products and significant revenues. He has done so with drive,
persistence, energy and enthusiasm. The entire Questcor organization thanks
Chuck for his service and wishes him well in his new endeavors. We look forward
to moving ahead to implement our vision of building long term value for
shareholders."

About Questcor

Questcor Pharmaceuticals, Inc. is a specialty pharmaceutical company that
acquires, markets and sells brand name prescription drugs for gastrointestinal
and neurological use through a U.S. direct sales force and international
distributors. Questcor currently markets five products in the U.S.: Nascobal(R),
the only prescription nasal gel formulation of Cyanocobalamin USP (Vitamin
B-12), that is approved for patients with severe deficiencies of Vitamin B-12
caused by Crohn's

                                       11
<PAGE>

Disease and MS; HP Acthar(R) Gel, an injectable drug that is commonly used for
certain neurological conditions; Ethamolin(R), an injectable drug used to treat
enlarged weakened blood vessels at the entrance to the stomach that have
recently bled, known as esophageal varices; Glofil(R)-125, which is an
injectable agent that assesses how well the kidney is working by measuring
glomerular filtration rate, or kidney function; and VSL#3(R), a patented
probiotic marketed as a dietary supplement, to promote normal gastrointestinal
function.

Note: Except for the historical information contained herein, this press release
contains forward-looking statements that involve risks and uncertainties. Such
statements are subject to certain factors, which may cause Questcor's results to
differ from those reported herein. Factors that may cause such differences
include, but are not limited to, Questcor's ability to accurately forecast and
create the demand for each of its products, the gross margins achieved from the
sale of those products, Questcor's ability to enforce its exchange policy, the
accuracy of the prescription data purchased from independent third parties by
Questcor, the sell through by Questcor's distributors, the inventories carried
by Questcor's distributors, and the expenses and other cash needs for the
upcoming periods, Questcor's ability to obtain finished goods from its sole
source contract manufacturers on a timely basis if at all, Questcor's need for
additional funding, uncertainties regarding Questcor's intellectual property and
other research, development, marketing and regulatory risks, and, to the ability
of Questcor to implement its strategy and acquire products and, if acquired, to
market them successfully as well as the risks discussed in Questcor's report on
Form 10-K for the calendar year ended December 31, 2003 and other documents
filed with the Securities and Exchange Commission. The risk factors and other
information contained in these documents should be considered in evaluating
Questcor's prospects and future financial performance. Questcor undertakes no
obligation to publicly release the result of any revisions to these
forward-looking statements, which may be made to reflect events or circumstances
after the date hereof or to reflect the occurrence of unanticipated events.

                                       12