Ketamine for the Treatment of Chronic Pain: A Comprehensive Review

Background Chronic pain significantly worsens the quality of life. Unlike neuropathic, musculoskeletal, postoperative pain, and cancer pain, chronic primary pain cannot be explained by an underlying disease or condition, making its treatment arduous. Objectives This manuscript intends to provide a comprehensive review of the use of ketamine as a treatment option for specific chronic pain conditions. Study Design A review article. Setting A review of the literature. Methods A search was done on PubMed for relevant articles. Results A comprehensive review of the current understanding of chronic pain and the treatment of specific chronic pain conditions with ketamine. Limitations Literature is scarce regarding the use of ketamine for the treatment of chronic pain. Conclusion First-line treatment for many chronic pain conditions includes NSAIDs, antidepressants, anticonvulsants, and opioids. However, these treatment methods are unsuccessful in a subset of patients. Ketamine has been explored in randomized controlled trials (RCTs) as an alternative treatment option, and it has been demonstrated to improve pain symptoms, patient satisfaction, and quality of life. Conditions highlighted in this review include neuropathic pain, fibromyalgia, complex regional pain syndrome (CRPS), phantom limb pain (PLP), cancer pain, and post-thoracotomy pain syndrome. This review will discuss conditions, such as neuropathic pain, fibromyalgia, complex regional pain syndrome, and more and ketamine's efficacy and its supplementary benefits in the chronic pain patient population. As the opioid crisis in the United States continues to persist, this review aims to understand better multimodal analgesia, which can improve how chronic pain is managed.