Fig. 1

Study flow. *Reasons for ineligibility occurring in >1 patient: current severe psychiatric illness (12 patients); did not have a mean daily pain rating of ≥3 to ≤ 9 in the week prior to the baseline visit (8 patients); did not meet Yunus and Masi criteria or ACR criteria (6 patients); had positive drug screen for illegal substances (4 patients); unwilling, unable, or inadvisable to discontinue prohibited medications during washout (3 patients). DB = double blind, ITT = intent to treat, OL = open label