Background

Chronic pain affects many individuals, and it is estimated that a substantial percentage of patients diagnosed with chronic pain suffer from neuropathic pain, a disorder that is often difficult to treat. With only moderate efficacy combined with increased side effects of existing first-line treatments, new therapeutic approaches are needed. Opioids have historically been used to treat chronic pain, however drugs that target the mu (MOR) and delta (DOR) receptors have been shown to result in addiction and abuse due to their ability to produce strong feelings of euphoria. The kappa opioid receptor (KOR) however has recently emerged as a promising new drug target for the development of non-additive analgesics due to its disassociation with addiction.