Introduction There is a paucity of effective therapeutic options for the millions of patients suffering from chronic and persistent pain disorders. Chronic pain, defined as the persistence of pain in the absence of injury or long after an inciting injury has resolved, represents a significant clinical challenge . Progressive increasing drug treatment "ladders" are often utilized in the management of persistent pain, starting with non-steroidal anti-inflammatory agents and progressing to the use of mild (codeine) and then strong (morphine) opioid drugs. Anticonvulsants and antidepressants have also been employed to reduce neuronal excitability characteristic of many pain disorders; however these drugs act through pathways not specific to pain-related pathways, and thus off-target effects of these drugs limit their utility. For example, opiate agonists have major side effects including somnolence, constipation and urinary retention; continuous use of opiates results in the development of tolerance requiring the escalation of dosage to achieve analgesia, which in turn increases the risk of drug abuse.