Intravenous Ketamine Infusion for the Treatment of Refractory Chronic Pain
According to the American Academy of Pain Medicine one hundred million Americans suffer from chronic pain. Many of those patients have failed to respond to conservative interventions such as injection therapy, medication management as well as numerous other treatment options including surgery. For certain types of pain conditions such as neuropathic pain, poststroke pain, fibromyalgia, complex regional pain syndrome, post herpetic neuralgia as well as other conditions the pain does not always respond to traditional therapeutic modalities. In these cases intravenous ketamine infusions may be a potential treatment option.
Ketamine has been used by the medical field in the United States for years and is commonly used as an anesthetic for surgical procedures for both humans and animals. Ketamine has a unique side effect profile that anesthesiologists take advantage of depending on the patient and surgical procedure being performed. Unlike other sedatives used for the operating room, ketamine is also a potent analgesic (pain reliever). The analgesic property of ketamine is unique because the pain relieving effect works very differently from traditional medications used in the operating room. Unlike opioid medications such as morphine, fentanyl or oxycodone, ketamines’ pain relieving properties are not dependent on the opioid receptor. Ketamine binds to the N-methyl-D-aspartate (NMDA) receptor and antagonizes it (shuts it off). If the NMDA receptors are activated there can be an association with increased pain (hyperalgesia), nerve related pain, decreased response to opioid medications and decreased functionality of opioid receptors. Because of this, ketamine is being studied for the treatment of pain in acute and chronic settings.
Note that research supporting the use of ketamine for chronic pain is not conclusive and continued research needs to be done. However numerous small trials have shown that ketamine is superior to placebo for a number of different chronic pain conditions, though consistent results have yet to be shown. Despite the lacking evidence and mixed efficacy from the trials, ketamine has been gaining popularity as a potential option for the treatment of chronic pain.
The increasing popularity at least in part stems from the currently limited pain medication options for patients and providers. Many patients find themselves dependent on the opioid class of medications which can present severe long term risks and side effects including respiratory depression and death. With the worsening opioid epidemic of the United States providers are more hesitant to prescribe opioids and there aren’t many viable options to replace the medication class. Patients and providers continue to look for medication options that avoid the opioid class entirely.
It is important to note that Ketamine is not without its risks of side effects and thus needs to be administered in a controlled setting once the risks and benefits have been discussed with your medical doctor. When administered in clinic, Ketamine is given by infusion versus orally as an oral dose would not be properly absorbed by the body. It is important to have properly trained personnel present for the duration of the infusion to monitor the patients vital signs and response to the infusion.
While further research is recommended it is important for patients to know that ketamine infusion treatment may be a viable option to provide pain relief for numerous conditions with some positive responses shown in managing central neuropathic pain, peripheral neuropathic pain, peripheral nerve injury, postherpetic neuralgia, complex regional pain syndrome, fibromyalgia and cancer pain. Because consistent supportive evidence to support the use of ketamine have not been demonstrated the treatment option is not typically covered by insurance carriers for the treatment of chronic pain. If you are interested in the therapy or have questions please do not hesitate to schedule an appointment for additional information.