5. Subjects must discontinue use of steroids, muscle relaxants, anticonvulsants, sodium channel blockers, topical analgesics, and needle-based therapies, including trigger point injections and acupuncture, at least 1 week prior to starting study medication and agree to stay off such therapies throughout the study. Continuation of nonsteroidal anti-inflammatories, antidepressants and opiates are allowed, provided they have reached a stable dose prior to study entry and maintain a stable dose throughout the study.