 The primary objective of this study is to determine the efficacy of droxidopa and droxidopacarbidopa in the treatment of pain associated with fibromyalgia. Secondary objectives include: evaluation of the effect of droxidopa and combinations of droxidopacarbidopa on signs and symptoms of fibromyalgia, evaluation of the effect of droxidopa and combinations of droxidopacarbidopa on the overall quality of life of fibromyalgia patients, evaluation of the dose-response relationship for droxidopa between different doses of droxidopa, carbidopa and combinations of droxidopacarbidopa in fibromyalgia patients, evaluation of the clinical benefit of treatment with different doses of droxidopa, carbidopa and combinations of droxidopacarbidopa in fibromyalgia patients, estimation of the optimal dose for relief of fibromyalgia pain using response surface methodology, and evaluation of the safety of droxidopa and droxidopacarbidopa treatments. 