Ketamine Infusion Therapy for Chronic Pain

Ketamine infusion therapy represents one of the most exciting advances in pain medicine over the past two decades. Originally developed as an anesthetic, ketamine — delivered at sub-anesthetic doses intravenously — has emerged as a powerful tool for patients with chronic pain conditions that have not responded adequately to conventional treatments.

Dr. Edward Rubin offers ketamine infusion therapy at his Long Island practice as part of a comprehensive, individualized pain management approach. Every infusion is medically supervised and tailored to each patient's specific diagnosis, pain history, and treatment goals.

What Is Ketamine?

Ketamine is an NMDA (N-methyl-D-aspartate) receptor antagonist. At sub-anesthetic infusion doses, it does not put patients to sleep — instead, it interrupts the way pain signals are processed in the central nervous system.

Chronic pain conditions often involve a process called central sensitization — the central nervous system becomes "wound up," amplifying pain signals far beyond what the original injury or condition would produce. Ketamine works directly on this mechanism, essentially resetting overactive pain pathways in the brain and spinal cord.

This is why ketamine can provide meaningful relief even when opioids, anti-inflammatory medications, nerve blocks, and other therapies have failed.

Conditions Treated with Ketamine Infusions

Dr. Rubin uses ketamine infusion therapy for a range of complex and treatment-resistant conditions, including:

• Complex Regional Pain Syndrome (CRPS) — Type I and Type II; ketamine is one of the most evidence-supported treatments for this condition
• Fibromyalgia — Central sensitization is a core feature; ketamine interrupts this cycle
• Chronic neuropathic pain — Including diabetic neuropathy, post-herpetic neuralgia, and nerve injury pain
• Failed back surgery syndrome — Persistent pain after one or more spinal surgeries
• Phantom limb pain — After amputation
• Migraine and chronic daily headache — Select refractory cases
• Cancer pain — When conventional opioid therapy is insufficient or causing intolerable side effects
• Post-surgical chronic pain — Thoracotomy pain, mastectomy pain, and other post-surgical syndromes

What to Expect During a Ketamine Infusion

Before the infusion: Dr. Rubin will review your full medical history, current medications, prior treatments, and imaging studies. A comprehensive evaluation ensures ketamine is appropriate for you and that we have clear goals for your series of infusions.

During the infusion: You will receive an IV line, and the ketamine is delivered slowly over 40 minutes to 4 hours depending on the protocol. You remain awake throughout. Some patients experience mild perceptual changes — a floating sensation, altered sense of time, or visual effects — which resolve fully when the infusion ends. Vitals are monitored continuously throughout the session.

After the infusion: You will need a driver. Most patients feel fine within an hour, though some report mild fatigue or grogginess for several hours. You should not drive or operate heavy machinery for the rest of the day.

The series: Research and clinical experience suggest that a series of infusions — typically 3 to 6 over 2–3 weeks — produces more durable results than a single session. Some patients receive maintenance infusions every few months to sustain relief.

How Effective Is Ketamine for Chronic Pain?

Response rates vary by condition. For CRPS, studies have reported significant pain reduction in 70–80% of patients following a course of infusions. For other neuropathic conditions, response rates of 50–70% are commonly reported in the literature.

Pain relief after ketamine infusions can last from weeks to months. Patients who respond well often find that the relief is qualitatively different from opioids — less sedating, with improvement in mood, function, and sleep alongside the pain reduction.

It is important to have realistic expectations. Ketamine is not a cure, and not every patient responds. Dr. Rubin will discuss your specific probability of benefit based on your diagnosis and history.

Is Ketamine Safe?

At sub-anesthetic doses under proper medical supervision, ketamine infusion therapy has a well-established safety profile. The main side effects during the infusion are the perceptual changes described above, which are temporary and expected.

Ketamine is not appropriate for patients with certain psychiatric conditions (including untreated schizophrenia or active psychosis), uncontrolled hypertension, or a personal history of ketamine abuse. Dr. Rubin screens all patients carefully before recommending infusion therapy.

Frequently Asked Questions

Does insurance cover ketamine infusion therapy? Currently, most insurance plans — including Medicare — do not cover ketamine infusions for chronic pain. This is considered an off-label use, and coverage determinations are evolving. Our office can provide documentation for possible self-pay reimbursement requests.

Will I be asleep or unconscious? No. Sub-anesthetic doses do not cause unconsciousness. You will be awake and aware throughout, though you may notice mild perceptual effects that resolve when the infusion ends.

Can I take my regular medications on the day of the infusion? This depends on the medication. Dr. Rubin will provide specific pre-procedure instructions at your consultation. In general, benzodiazepines and high-dose opioids may reduce ketamine's effectiveness and are typically adjusted before the series.

How soon will I know if it's working? Some patients notice improvement after the first or second infusion. Others need to complete the full series before judging response. Dr. Rubin will reassess your pain levels throughout the treatment course.

What if ketamine doesn't help? If you do not respond after a complete series, Dr. Rubin will reassess and discuss other interventional options — including spinal cord stimulation, intrathecal pump therapy, or other approaches appropriate to your diagnosis.

Schedule a Ketamine Consultation

Ketamine infusion therapy is offered at our Lake Success office and is reserved for patients who have completed a thorough evaluation with Dr. Rubin. Call our office at 516-492-3100 or use the form below to request a consultation.