The objective of this trial is to evaluate the safety and efficacy of Xyrem® in long term use.

The trial is an open-label safety and efficacy study of subjects with fibromyalgia who completed either study 06-008 or 06-009. Total duration is up to 40 weeks of trial participation.

Inclusion Criteria:

• Subject has qualified for and completed either study 06-009 (NCT00423813) or 06-008 (NCT00371137).
• Subject is able, in the opinion of the investigator, to take Xyrem® for approximately 9-1/2 months.

Exclusion Criteria:

• Subject terminated early from either study 06-009 or 06-008.
• Subject experienced any serious adverse event related to study drug in either study 06-009 or 06-008.
• Subject, in the opinion of the investigator, experienced an adverse event in 06-009 or 06-008 that may prevent him/her from safely participating in this study.