FDA Accepts Orphan Medical Plan Regarding Xyrem NDA

Minneapolis, MN - August 28, 2001

Orphan Medical, Inc. announced that the U.S. Food and Drug Administration (FDA) has accepted the Company's plan for a complete response to the Agency's Approvable Letter dated July 2, 2001, regarding Xyrem® (sodium oxybate) oral solution as a treatment for narcolepsy, particularly the symptom of cataplexy. This response describes the planned amendment to the Company's New Drug Application (NDA). The Company now estimates the amendment can be submitted by the middle of the fourth quarter 2001. The FDA has up to six months from the date of submission to take action.

In addition to providing the FDA with a safety update of ongoing clinical trials, the Company will also provide respiratory data generated in conjunction with all-night polysomnographic recordings included in a prior Orphan Medical trial. If these data are acceptable to the FDA, an additional acute exposure trial in respiratory compromised patients will be conducted post approval. Revisions to product labeling and the Company's risk management program will also be included in the amendment. The manufacturer of Xyrem is currently undergoing a re-inspection for current Good Manufacturing Practice (GMP) by FDA. Once the manufacturer has successfully met GMP requirements, a pre-approval inspection for the manufacture of Xyrem may be scheduled.

Narcolepsy is a chronic neurological disorder affecting an estimated 100,000 to 125,000 Americans, whose main symptoms are excessive daytime sleepiness and cataplexy. Cataplexy is a debilitating symptom characterized by loss of muscle control in response to strong emotions such as laughter, anger, or surprise. In its most severe form, cataplexy can cause a person to collapse during waking hours.

Orphan Medical acquires, develops, and markets pharmaceuticals of high medical value for inadequately treated and uncommon diseases. The Company serves three strategic therapeutic market segments that are characterized by well-defined patient populations and served by physician specialists: oncology support, antidotes and sleep disorders. Orphan Medical's Internet Web site address is http://www.orphan.com.