Neuropathy is a general term for disorders of the peripheral nervous system. Approximately 8% of the general population (24 million people in the United States) suffer from neuropathic pain including painful diabetic neuropathy, PHN, postmastectomy pain and phantom limb pain. The costs associated with the treatment of neuropathic pain exceed $4 billion annually in the United States. Nonprescription oral pain relievers, including acetaminophen and NSAIDs, may provide some temporary pain relief but are not effective for long-term treatment of severe pain. Prescription anti epileptic medications approved for some forms of neuropathic pain such as Lyrica® and Cymbalta® are also not effective for all patients.
Pain is one of the most common, persistent, and debilitating symptoms associated with cancer. Two-thirds of cancer patients report pain while undergoing treatment. Cancer pain can result from the disease itself or from the treatment of the disease. The estimated annual U.S. market size for breakthrough cancer pain treatment is $850 million. In the pharmacologic treatment of cancer pain, many analgesic drugs, from NSAIDs to strong opiates, are used. Generally, such drugs provide only limited relief and frequently produce undesirable side effects.