Ketamine pills could ease debilitating CRPS pain – new trial underway
NCT ID NCT06419985
First seen Jun 27, 2026 · Last updated Jul 28, 2026 · Updated 2 times
Summary
This phase 2 trial will test whether extended-release ketamine tablets can reduce pain in 65 adults with complex regional pain syndrome (CRPS), a chronic condition causing severe, often burning pain. Participants will take either 80 mg or 160 mg of ketamine daily for several weeks. The study is open-label, meaning everyone knows they are getting the drug, and it focuses on pain scores, quality of life, and safety.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Ketamine extended-release tablets
- What this could lead to
- If successful, this could provide a new oral treatment option to ease chronic pain for people with complex regional pain syndrome.
- What could go wrong
- This is an early-phase, open-label trial with no placebo group, so results may be influenced by expectation. The small size (65 people) also limits how broadly findings can be applied.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
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About 65 people
The number the study aims to enrol. It can still change while the study runs.
- Expected to start
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Jan 2027
An estimate. Start dates often move.
- Expected to finish
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Jul 2029
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 to 64 years
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Male and female participants between 18 and 64 years of age, inclusive, at Screening Visit. 2. Participants with a documented history of CRPS of at least 6 months at Visit 1. 3. At least one sign in two of the categories of The Budapest Criteria for CRPS to support the diagnosis of CRPS. 4. Stable individual regular standard treatment regimen for CRPS pain, i.e., no change in drug and non-drug treatments for at least 4 weeks prior to Screening Visit and anticipated to remain stable throughout the study. 5. No surgery, denervation procedures or neural blockade within 1 month of Screening Visit. 6. Participants on ketamine therapy at Screening Visit must agree to discontinue use for at least 14 days prior to the Baseline Observation Period. 7. Agree to discontinue any prohibited medications within prior to 14 days of the Baseline Observation Period and for the duration of the study. 8. Average daily CRPS pain intensity score in the affected limb of ≥5 and ≤9 on an 11-point (0-10) NRS averaged over 7 days prior to Baseline Visit (Visit 1). This will be based on completion of at least 5 daily pain diary entries during the week prior to Visit 1, with no more than one 24-hour pain intensity score of zero or more than one 24-hour pain intensity score of 10. 9. Participants willing and able (e.g., mental and physical condition) to participate in all aspects of the trial, including use of medication, completion of subjective evaluations, attending scheduled clinic visits, completing telephone contacts, and compliance with protocol requirements as evidenced by providing signed written informed consent at Screening Visit. 10. For persons of reproductive potential: use of highly effective contraception (females: barrier (condom, diaphragm, sponge, cervical cap) and/or oral, implantable rod, or intrauterine device birth control; males: barrier (condom)) for at least 1 month prior to screening and agreement to use such a method during study participation and for an additional 6 weeks after the end of study intervention administration. Exclusion Criteria: 1. Known or suspected cardiovascular disease, arrythmias, and/or respiratory issues. 2. Abnormal EKG results, abnormal blood pressure (SBP \<90 or ≥ 140; DBP \<50 or ≥ 90) and/or heart rates (\<50 or \>110). 3. Known or suspected psychotic illness or neurologic disease. 4. Known or suspected elevated intraocular and/or intracranial pressure. 5. Known or suspected renal or urologic conditions or symptoms (i.e., bladder pain syndrome, interstitial cystitis), and/or abnormal baseline urinalysis results. 6. Known or suspected hyperthyroidism. 7. Allergy, hypersensitivity, or intolerance to ketamine or any of the investigational product excipients. 8. Participants receiving opioids ≥30 mg/day morphine milligram equivalents (MME), whether as part of their individual standard treatment regimen for CRPS pain or in context with any other indication, within the last two weeks prior to Visit 1. 9. Positive urine screen for any of the following: cocaine, amphetamine, methamphetamine, PCP, opioids, THC (other than medication used for individual standard treatment of pain) at Visit 1. 10. Known or suspected acute or chronic alcoholism, delirium tremens, or toxic psychosis. 11. Meet DSM-5 criteria for current or past substance use disorder within the last 5 years for any psychoactive substances other than nicotine or caffeine. 12. Known hepatic dysfunction or serious liver disease, including presence of aspartate aminotransferase (AST) levels ≥ 2 X upper limit of normal and/or alanine aminotransferase (ALT) levels ≥ 2 X upper limit of normal and/or total bilirubin ≥ 1.5 X upper limit of normal 13. Abnormal urinalysis, urine culture or abnormal creatinine 14. Evidence of moderate or severe renal impairment (CRCL \<60 ml/min) or participants with renal failure who are on any form of dialysis. 15. Current or previous history of seizures. 16. A positive pregnancy test/confirmed pregnancy test at the screening or baseline visit. 17. If Ask Suicide-Screening Questionnaire (ASQ) is positive at Grade 2 (moderate), subject will be excluded. 18. Any other condition of the patient that in the opinion of the investigator may compromise evaluation of the trial treatment or may jeopardize participant's safety, compliance or adherence to protocol requirements. 19. Previous enrollment in this trial or participation in any other clinical trial within the past 30 days prior to enrollment.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
The full official record for this study. This one lists no contact details, but it is the first place any would appear.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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Pain Center, Keck Medical Center of University of Southern California
Los Angeles, California, 90033, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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- Magnetic pulses to the brain aim to quiet CRPS pain
- Pain drug lyrica put to the test for rare limb condition – but trial stalls
- Teens with chronic pain try dance as medicine
- Brain scans aim to unlock secrets of chronic pain in kids