Questcor Announces Presentation of Data on H.P. Acthar Gel at American Epilepsy Society Annual Meeting.

UNION CITY, Calif. -- Questcor Pharmaceuticals, Inc. (AMEX:QSC) today announced that data from six posters related to the company's marketed product H.P. Acthar([R]) Gel (repository corticotropin injection) will be presented at the annual meeting of the American Epilepsy Society (AES) December 1-5 in San Diego, California. These six posters discuss use of H.P. Acthar Gel in the treatment of Infantile Spasms, a life-threatening form of childhood epilepsy. Questcor is seeking U.S. Food and Drug Administration (FDA) approval of H.P. Acthar Gel, a natural adrenocorticotropic hormone (ACTH), for the treatment of Infantile Spasms. H.P. Acthar Gel is currently approved for a number of diseases and disorders, including the treatment of Multiple Sclerosis exacerbations.

The Scientific Exhibit highlighting these posters will take place Monday, December 4th from 8:00 a.m. to 11:00 a.m. PST in Room 5A of the San Diego Convention Center. Topics presented in this exhibit include:

* Treatment of Infantile Spasms with Adrenocorticotropic Hormone

* Spectrum of Adrenocorticotropic Hormone Use

* Long-term Outcome of Treatment with Adrenocorticotropic Hormone

* Safety of Adrenocorticotropic Hormone

* Safety and Monitoring Protocols in Infantile Spasms

* Infantile Spasms Case Studies: Efficacy of Adrenocorticotropic Hormone

Questcor provided an unrestricted educational grant in support of this scientific exhibit.

About Infantile Spasms - Infantile spasms (IS) is a seizure disorder of early childhood also known as West Syndrome. The onset is predominantly in the first year of life, typically between 3 to 6 months. The typical pattern of IS is a sudden bending forward and stiffening of the body, arms, and legs; although there can also be arching of the torso. Spasms tend to begin soon after arousal from sleep. Individual spasms typically last for 1 to 5 seconds and occur in clusters, ranging from 2 to 100 spasms at a time. Infants may have dozens of clusters and several hundred spasms per day. Infantile spasms usually stop by age 5, but are often replaced by other seizure types. IS is characterized by seizures, hypsarrhythmia (abnormal, chaotic brain wave patterns), and mental retardation. Other neurological disorders, such as cerebral palsy, may be seen in 30-50% of those with IS. The incidence of IS is estimated to be about 1 per 2,000 to 4,000 live births. It is the most frequent type of epileptic encephalopathy, the group of conditions in which epilepsy determines cognitive deterioration. No drug is currently approved in the United States for the treatment of IS.

About Acthar Gel - H.P. Acthar Gel([R]) is a natural adrenocorticotropic hormone (ACTH) designed to provide a prolonged release after intramuscular or subcutaneous injection. Acthar Gel is currently indicated for the treatment of acute exacerbations of multiple sclerosis, and for several other diseases and disorders.

For full prescribing information and safety information on Acthar Gel, please visit http://www.acthar.com.

About Questcor - Questcor Pharmaceuticals, Inc.([R]) (AMEX:QSC) is a specialty pharmaceutical company that develops and commercializes novel therapeutics for the treatment of neurological disorders. Questcor currently markets H.P. Acthar([R]) Gel (repository corticotropin injection), an injectable drug indicated for the treatment of exacerbations associated with multiple sclerosis and Doral([R]) (quazepam) that is indicated for the treatment of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings. For more information, please visit www.questcor.com.

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 its products, the gross margin achieved from the sale of its products, Questcor's ability to enforce its product returns 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 potential future need for additional funding, Questcor's ability to utilize its net operating loss carry forwards to reduce income taxes on the sale of its non-core products, research and development risks, uncertainties regarding Questcor's intellectual property and the uncertainty of receiving required regulatory approvals in a timely way, or at all, and 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 annual report on Form 10-K for the year ended December 31, 2005 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.