Complex Regional Pain SyndromeLDN-CRPSNCT02502162
Low-Dose Naltrexone for the Treatment of Complex Regional Pain Syndrome
A study testing LDN in people with Complex Regional Pain Syndrome, run by Stanford University at 1 site in United States.
Trial summary
The investigators are testing treatment with low-dose naltrexone (LDN) for symptom relief of complex regional pain syndrome (CRPS). Study participants will be randomly assigned to receive either LDN or placebo for a period of several weeks. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Complex Regional Pain Syndrome
- What is being tested?
- LDN
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- Jun 2015to Jul 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Upper and/or lower extremity CRPS
- On stable treatment for 1 month
- CRPS for at least 1 year
- Meet the Budapest criteria for CRPS at time of the study.
Who cannot join
- Any known allergy to naltrexone or naloxone
- Use of prescription opioid analgesics or illegal opioid use
- Current or planned pregnancy.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Stanford University
Palo Alto, California, 94304
Birute Gedrimaite, 650-497-0485, birute@stanford.edu
Sean Mackey, MD, PhD
About this study
The investigators are testing treatment with low-dose naltrexone (LDN) for symptom relief of complex regional pain syndrome (CRPS). Study participants will be randomly assigned to receive either LDN or placebo for a period of several weeks. During this period participants will be asked to attend either in-person or virtual study visits and complete questionnaires.
- Conditions
- Complex Regional Pain Syndrome
- Being tested
- LDN, Placebo
- Medical subject headings
- Complex Regional Pain Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LDNDrug
PlaceboDrug
Sugar pill
| Study group | Role | What they receive |
|---|---|---|
| LDN | Experimental | Naltrexone HCL, 4.5 mg, Once a day. Receives: Drug: LDN |
| Placebo | Placebo comparator | Sugar pill Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in pain severity
Daily pain reports on a 0-10 numerical rating scale for pain, where 0=no pain and 10=pain as bad as you can imagine
Measured: Approximately 4 weeks after conclusion of treatment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2015 (estimated)
- Study startJun 2015
- Primary completionJul 2027 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Complex Regional Pain SyndromeStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sean Mackey, Stanford University
- Investigators
- Sean Mackey, MD, PhD, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02502162
- Sponsor's protocol ID
- 33607
- Acronym
- LDN-CRPS
- Status last verified
- May 2025
- First submitted
- 15 Jul 2015
- Last updated
- 29 May 2025
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Low-Dose Naltrexone for the Treatment of Complex Regional Pain Syndrome
- ClinicalTrials.gov ID
- NCT02502162
- Acronym / sponsor ID
- LDN-CRPS / 33607
- Conditions
- Complex Regional Pain Syndrome
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- Jun 2015
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Jul 2027 (estimated)
- First posted
- 20 Jul 2015 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The investigators are testing treatment with low-dose naltrexone (LDN) for symptom relief of complex regional pain syndrome (CRPS). Study participants will be randomly assigned to receive either LDN or placebo for a period of several weeks. During this period participants will be asked to attend either in-person or virtual study visits and complete questionnaires.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| LDN | Experimental | Drug: LDNNaltrexone HCL, 4.5 mg, Once a day. |
| Placebo | Placebo comparator | Drug: PlaceboSugar pill |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Upper and/or lower extremity CRPS
- On stable treatment for 1 month
- CRPS for at least 1 year
- Meet the Budapest criteria for CRPS at time of the study.
Key exclusion criteria (3 listed)
- Any known allergy to naltrexone or naloxone
- Use of prescription opioid analgesics or illegal opioid use
- Current or planned pregnancy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LDN | Drug | LDN |
| PlaceboSugar pill | Drug | Placebo |
Primary outcome
Changes in pain severity
Time frame: Approximately 4 weeks after conclusion of treatment.
Daily pain reports on a 0-10 numerical rating scale for pain, where 0=no pain and 10=pain as bad as you can imagine
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 May 2025.
Related trials for Complex Regional Pain Syndrome
Enrolling by invitationPhase 4
Low Dose Naltrexone Therapy for Complex Regional Pain Syndrome
Complex Regional Pain Syndrome, Chronic Pain
RecruitingPhase 3
Evaluation of IV AMBTX-01 (Neridronate) for Treatment of CRPS Type 1 (CRPS-RISE)
Complex Regional Pain Syndrome Type I
Recruiting
The Effectiveness of Conservative Treatment in Patients With Complex Regional Pain Syndrome.
CRPS (Complex Regional Pain Syndromes)
RecruitingPhase 3
Phase 3, Open-Label Extension Study of AMBTX-01 (Neridronate) for Complex Regional Pain Syndrome Type 1
Complex Regional Pain Syndrome Type I
Active, not recruiting
Transcranial Magnetic Stimulation for Chronic Neuropathic Pain
Chronic Neuropathic Pain, Post-Stroke Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sean Mackey, MD, PhD principal investigator
Stanford University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing LDN in people with Complex Regional Pain Syndrome, run by Stanford University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Birute Gedrimaite ((650) 497-0485, birute@stanford.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in pain severity (time frame: Approximately 4 weeks after conclusion of treatment.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 May 2025.