Ketamine for chronic pain conditions

Just as there are many different types and causes of chronic pain, there are multiple treatment options. These can range from over-the-counter medications such as acetaminophen or non-steroidal anti-inflammatory (NSAID) drugs to prescription medications such as muscle relaxants and stronger pain killers. Often in chronic pain conditions, these first-line treatment options may fail to alleviate pain in the long-term. At this point, patients may pursue other treatment options.

About ketamine

Ketamine was originally developed to be an anesthetic for use during surgeries, is now also commonly used as a treatment for the management of chronic pain and depression.¹  Some of the chronic pain conditions that ketamine has been used to treat include neuropathic pain, fibromyalgia, and postherpetic neuralgia.²

How does ketamine work?

Ketamine has antihyperalgesic, anti-inflammatory, and antidepressant effects¹ – this is what makes it useful to treat a variety of medical conditions. In can also be administered in a variety of ways, including intravenous (IV), oral, subcutaneous, transdermal, and spinal.¹

Ketamine works by acting on a cellular receptor called N-methyl-D-aspartate (NMDA).² This receptor plays a role in regulating pain and is located in the nervous system.²  It is thought that ketamine blocks the pain signals transmitted by this receptor to the brain. The pain-relieving effects of ketamine have been reported to last up to 12 weeks.³ 

Ketamine for complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a form of chronic pain that usually occurs after an injury to an arm or leg. This pain can continue long after the injury has occurred. Multiple studies have reported lasting pain relief in patients with CRPS who were treated with ketamine infusions.⁴

Ketamine for chronic neuropathic pain

Neuropathic pain can be a complex and difficult pain condition to treat. This condition usually occurs due to nerve damage that permanently alters the transmission of pain signals to the brain. Some studies have found positive effects of ketamine infusion for the treatment of chronic neuropathic pain such as postherpetic neuralgia, fibromyalgia, and diabetic neuropathy.⁴

When ketamine doesn’t work

For patients with chronic pain who do not find relief with ketamine, other treatment options are available. These can include treatment with lidocaine infusions. Lidocaine infusion have been described as a promising option to treat pain conditions when other treatments fail.

Are ketamine infusions covered by OHIP?

Ketamine infusions are not currently covered by OHIP.

References

1. Bell, R. F., & Kalso, E. A. (2018). Ketamine for pain management. Pain reports, 3(5), e674. https://doi.org/10.1097/PR9.0000000000000674
2. Wadehra, S., Gunten, CF. Ketamine for Chronic Pain Management: Current Role and Future Directions https://www.practicalpainmanagement.com/patient/treatments/medications/ketamine-chronic-pain-management-current-role-future-directions
3. Shteamer, Jack Williams et al. “How effective is ketamine in the management of chronic neuropathic pain?.” Pain management vol. 9,6 (2019): 517-519. doi:10.2217/pmt-2019-0032
4. Maher, D. P., Chen, L., & Mao, J. (2017). Intravenous Ketamine Infusions for Neuropathic Pain Management: A Promising Therapy in Need of Optimization. Anesthesia and analgesia, 124(2), 661–674. https://doi.org/10.1213/ANE.0000000000001787
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