Orphan Medical Announces the Completion of Clinical Portion of EXCEEDS Excessive Daytime Sleepiness Trial

Minneapolis, MN - July 27, 2004

Orphan Medical, Inc. announced today that all patients have completed the clinical portion of its second Phase III(b) trial assessing Xyrem(R) (sodium oxybate) oral solution to treat excessive daytime sleepiness (EDS) associated with narcolepsy. The Company expects to release initial results from this trial by mid-September. Xyrem is currently the first and only approved treatment for cataplexy associated with narcolepsy. EDS is a universal symptom of narcolepsy frequently accompanied by unavoidable episodes of sleep.

This Phase III(b) trial, known as EXCEEDS (Evaluation of Xyrem to Check Efficacy in Excessive Daytime Sleepiness), is a double-blind, placebo-controlled, parallel multi-center randomized study designed to evaluate improvement in EDS when Xyrem is used with or without modafinil (Provigil(R)). The primary endpoint of the trial is the reduction of excessive daytime sleepiness as measured by the objective measure Maintenance of Wakefulness Test.

"Following the strong results of our first EDS trial, we are eager to see the results of the EXCEEDS trial," said John Bullion, Orphan Medical Chief Executive Officer. "The results of the two Phase III(b) trials will be analyzed and submitted to the U.S. Food and Drug Administration (FDA) as a supplemental New Drug Application (sNDA) toward the end of this year. The sNDA filing will position the Company for an FDA decision in 2005 that could allow us to expand the use of Xyrem to all of narcolepsy, a market that we estimate to be $300 million in total size."

In its previous trial, SXB-15, which assessed Xyrem in treating EDS associated with narcolepsy, the Company saw positive results across all primary measures. The primary endpoints of the trial were changes in the Epworth Sleepiness Score (ESS) and Clinical Global Impressions of Change (CGIc). The ESS results were statistically significant at the 6.0 gram and 9.0 gram (p less than 0.001) doses. A statistically significant response (p less than or equal to 0.001) was seen at all Xyrem dose levels in the CGIc using a responder analysis that classified "responders as patients who were "much improved" or "very much improved" as assessed by the treating physician.

Narcolepsy is a chronic, debilitating neurological disease. Cataplexy, a sudden loss of muscle tone, is usually triggered by strong emotions such as laughter, anger, or surprise. As such, patients often selectively isolate themselves from interaction with others resulting in a worsening effect on a patient's quality of life. Narcolepsy afflicts approximately 100,000 to 140,000 Americans with about 50,000 to 75,000 patients receiving some form of treatment for their symptoms. An estimated sixty to ninety percent of those with narcolepsy suffer from cataplexy. All patients with narcolepsy suffer from excessive daytime sleepiness.

Upcoming Webcast

Orphan Medical also announced that it will participate in the Banc of America 2004 Specialty Pharmaceutical Conference on July 29, 2004, at 3:00 pm Eastern discussing specialty pharmaceutical markets. The conference will be webcast live over the Internet and you can listen to the Orphan Medical portion by visiting www.orphan.com

Orphan Medical acquires, develops, and markets pharmaceuticals of high medical value for inadequately treated and uncommon CNS diseases treated by specialist physicians. The lead product for the company is Xyrem, which is the first and only approved treatment for cataplexy associated with narcolepsy. Xyrem is also being assessed as a treatment for the full range of narcolepsy symptoms including excessive daytime sleepiness and for the treatment of fibromyalgia. Orphan Medical's Internet Web site address is www.orphan.com

The information in this press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. A number of factors could cause actual results to differ materially from the Company's assumptions and expectations. These are set forth in the cautionary statements included in Orphan Medical's most recent Form 10-Q or Form 10-K filed with the Securities and Exchange Commission. (These documents can be accessed through the Orphan Medical Web site at http://www.orphan.com ). All forward-looking statements are qualified by, and should be considered in conjunction with, such cautionary statements.