A 9-week randomized double-blind, multi-center study of 172 patients, who after 1 week baseline evaluation are randomized to either fixed dose pregabalin starting at 75 mg BID for one week and increased to 150 mg BID for 7 weeks or flexibly dosed pregabalin given BID (75-300 mg/d) increased gradually over 4 weeks then maintained at that same dosing for 4 weeks.It is proposed that use of flexible dosing combined with nightly dosing would have similar pain relief to fixed dosing, would improve adherence, would have less side effects and would be more likely to improve sleep.

Inclusion Criteria:

• diagnosis of fibromyalgia by ACR criteria
• ambulatory patients
• complete of 5 pain diaries during 1 week evaluation
• other inclusion criteria may apply

Exclusion Criteria:

• pregnant or of childbearing potential not using contraceptives
• use of pregabalin in the past
• concomitant use of opioids or gabapentin
• estimated creatinine clearance less than 60
• other criteria may apply