Ketamine Infusions for Managing Chronic Pain

Chronic pain affects over 76 million Americans, and the annual cost of treating patients with chronic pain exceeds that of heart disease, diabetes, and cancer, to the tune of a whopping $635 billion. Various treatment options are available, but many individuals find little or no success with traditional interventions.

Prescription pain medications usually work to interfere or dull the influence of pain signals rather than target the root of the problem. And these medications are also associated with negative side effects like physiological dependence. At Hudson Medical, we take a multidisciplinary approach to pain management with a variety of novel treatment modalities, such as ketamine for treating chronic pain.

Ketamine is a potent analgesic and, at low doses, has been proven effective for helping the brain regenerate its pain-modulating pathways. It is often considered for treatment-resistant patients and even helps reverse a patient’s tolerance to opioids and other medications.

Our pain management team at Hudson Medical has experience using ketamine over the last dozen years, finding it extremely effective at rapidly reducing pain symptoms when using the right dose for the right indication.

What Is Ketamine and What Is a Ketamine Infusion?

Ketamine is a medication that was first indicated for anesthesia in the 1960s. It has since been found as a promising therapy for pain relief and treatment-resistant depression. Ketamine’s primary benefit as pain medicine is its fast-acting relief and antidepressant properties. In particular, it is hailed as an attractive option in cases of non-response to conventional medications or therapies.

Regarding pain relief, ketamine was introduced as an adjunctive medicine helping to reduce the need for stronger analgesics like morphine. It was typically indicated for surgical patients who have developed a tolerance for opioids or who want to avoid opioid analgesics in the perioperative setting. Today, specialized health facilities like Hudson Medical offer ketamine infusions in an outpatient procedure.

Ketamine infusion is a specialized technique that delivers low doses of ketamine via intravenous (IV) drip to manage moderate to severe pain and is often used in tandem with other analgesic therapies. At Hudson Medical, ketamine infusions are offered as part of their state-of-the-art treatment modalities and are administered at the hands of trained anesthesiologists and chronic pain specialists.

When Should Ketamine IV Be Used?

Ketamine IV is most frequently found to relieve acute pain in emergency departments and the perioperative period in patients with refractory pain. More and more, ketamine infusion is being used for analgesic therapy in outpatient settings, especially for neuropathic pain, osteoarthritis, fibromyalgia, pain from spine trauma, chronic migraine, and complex regional pain syndrome.

Ketamine only works as an analgesic in conditions that involve a specific set of receptors responsible for modulating pain. Not all patients experiencing pain have these receptors activated; therefore, ketamine must be prescribed with care. Ketamine should be avoided by patients with poorly controlled cardiovascular disease, psychosis, pregnancy, liver disease, substance abuse problems, elevated intracranial pressure, and glaucoma.

How Does Ketamine Work to Relieve Pain?

Ketamine is thought to target a specific chemical receptor in the brain known as N-methyl-D-aspartate, or NMDA. NMDA receptors are found in the central nervous system as well as in other parts of the body, and their function is to modulate the pain signal. Specifically, NMDA receptors have a role in the amplification of pain signals, development of central sensitization, and opioid tolerance.

Ketamine interacts with NMDA receptors to suppress pain transmission. When ketamine binds with NMDA receptors, it stimulates a rapid increase in glutamate production. Glutamate is a neurotransmitter involved in cognitive function and primarily facilitates communication within the brain by encouraging the growth of new synapses, or connections, between neurons. This process is called synaptogenesis.

Individuals who experience chronic pain or stress over a long period of time start to lose these neural connections leaving pain-modulating pathways impaired. By encouraging glutamate production, ketamine helps your body regenerate these vital neural connections, even helping reduce or reverse opioid tolerance. With an improved ability to regulate pain signals, even a single treatment cycle can provide lasting relief.

How Does Ketamine Dosage Affect Glutamate?

The amount of ketamine used determines the medication’s effect on a patient. Specifically, ketamine dosage plays an important role in the glutamate system. At high doses, ketamine seems to block glutamate, weakening neural signals and, hence, making it effective as an anesthetic. But at low doses, ketamine causes a glutamate surge, resulting in synaptogenesis and helping restore the brain’s efforts to regulate pain.

Through its ability to build new neural connections, glutamate produces a variety of effects. Synaptogenesis is a possible mechanism that affects mood, thought patterns, and cognitive function, making it a prime target for managing how we process pain.

What Are the Effects and Benefits of Ketamine?

Used appropriately and in the hands of medical professionals, ketamine has sedative, analgesic, and amnesic effects that benefit its use as a pain reliever. Another major benefit of ketamine is its rapid action, improving pain symptoms within minutes to hours.

Ketamine further produces short-term dissociative effects—when abused, ketamine can alter people’s consciousness and perceptions of themselves and their environment. At subanesthetic-doses, ketamine use may produce milder dissociative effects, which individuals report as feeling weird or loopy. Most of these effects peak within an hour of administration and resolve by 2 hours post-infusion.

While the relationship between dissociation and pain relief is something that researchers are trying to better understand, there may be a psychological benefit for people to view their chronic pain differently following dissociation. In other words, they may be able to dissociate from feelings of acute pain.

How Is a Ketamine Infusion Performed?

A ketamine infusion is administered through a slow, constant intravenous (IV) drip. You may feel a small prick as the IV is placed, but you should feel relatively comfortable through the rest of the procedure. A big benefit of ketamine infusions is how quickly they work, often within hours. You will begin to feel a calming effect from the ketamine even during treatment delivery.

The duration and dosage depend on the anesthesiologist’s recommendation, and the patient will be monitored for their response. Standard dosing protocols have determined 0.5 to 2.0 mg/kg per hour with a total dosage of at least 80 mg infused over a period of >2 hours to be appropriate. In refractory cases, dosages up to 7.0 mg/kg per hour have been successfully used in an ICU setting.

On average, ketamine infusion therapy calls for a series of 6 infusions over 2 or 3 weeks. Initial dosages may be altered and monitored for evidence of a positive dose-response relationship. A long-term maintenance phase follows an initial treatment, which may require an occasional booster IV.

What Are the Risks of Ketamine?

Risks of ketamine include potential addictive properties; however, ketamine infusions deliver very low doses of medication administered by a medical professional to monitor each patient’s response and adjust it from there. Ketamine infusion can induce certain temporary side effects, including dizziness, mild hallucinations, elevated heart rate, nausea, fatigue, floating sensations, or fuzzy vision.

When misused, the dissociative effect of ketamine can change your sense of sight and sound, and people have reported feeling out of touch with their surroundings and themselves. The American Society of Anesthesiologists president, John Abenstein, MD, says, “Outside of the clinic, ketamine can cause tragedies, but in the right hands, it is a miracle.”

Is Ketamine Effective at Relieving Pain?

While a large body of literature is focused on the effective use of ketamine in perioperative or emergency settings, a growing number of studies support ketamine infusions for the treatment of chronic pain in an outpatient setting.

A study conducted in 2010 randomized patients with neuropathic pain caused by spinal cord injury to receive daily intravenous ketamine infusion or placebo infusion for a week. The ketamine group reported significant improvements in pain scores compared to the control group up to 2 weeks following the intervention.

A separate study conducted in 2009 treated patients with chronic pain from Complex Regional Pain Syndrome with either low-dose ketamine or placebo. Similarly, the patients who received ketamine infusions reported significantly lower pain levels during the 12-week follow-up period compared to patients who received placebo.

What Is the Role of Ketamine Infusion in Pain Management?

We can’t emphasize enough that when seeking out ketamine infusion therapy, you must approach the right medical specialists, including a trained anesthesiologist and chronic pain managers.

At Hudson Medical, we create custom treatment plans for each patient that involves not only novel therapies but encourages a comprehensive approach to pain relief. If you are curious about ketamine IVs and whether they are an option for you, schedule a consultation with one of our Pain Management specialists at Hudson Medical today!


Bell RF, Kalso EA. Ketamine for pain management. Pain Rep. Published online August 9, 2018. doi: 10.1097/PR9.0000000000000674.

Collins S. What you need to know about ketamine’s effects. Published online February 27, 2018. Accessed May 4, 2021.

Wadehra S, von Gunten CF. Ketamine for chronic pain management: current role and future directions. Practical Pain Management. Updated February 20, 2019. Accessed May 4, 2021.