Chronic PainNCT02192398
Effect of Guanfacine on the Reversal of Opioid-induced Hyperalgesia (OIH)
A study testing Guanfacine in people with Chronic Pain, run by Massachusetts General Hospital at 1 site in United States.
Trial summary
Combination of guanfacine with opioid medication as a standard treatment for chronic pain. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Chronic Pain
- What is being tested?
- Guanfacine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2014to Oct 2022
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 18-65 years old
- Chronic neck or back pain condition for at least 6 months
- VAS score of 4-8, despite opioid therapy
- On a stable morphine equivalent dose of at least 60mg/day and ≤ 240mg/day for at least 3 months
Who cannot join
- Has taken Methadone, Suboxone, Fentanyl, and/or Tramadol in the last six (6) months
- Has taken guanfacine (or other alpha-2AR agonists) in the last six (6) months
- Changes to current or adding new pain treatment while enrolled in the study (i.e. opiates, epidural steroid injection) will be reviewed by the study physician
- Unable to independently provide informed written consent
- Sensory deficits at site of QST, such as peripheral neuropathy
- Intolerable allergies or has had a severe adverse reaction to study medication (i.e. guanfacine, lactose, vitamin B2 a.k.a. riboflavin)
Show all 21Show fewer
- Takes vitamin B2 > 1.6mg/day during the study
- Pregnant or breastfeeding
- Pending litigation related to neck or back pain
- Diagnosed with Raynaud's syndrome
- Has other chronic pain conditions such as fibromyalgia or joint osteoarthritis that are predominant over back and neck pain with regard to its intensity (VAS)
- Has known pre-existing severe cardiovascular disease (i.e. arrhythmia - prolonged QT interval > 440ms), cerebrovascular disease/accident (i.e., stroke), hepatic or renal impairment, CNS condition, metabolic condition, or history of syncope
- Hypotension (SBP < 90 mmHg and DBP < 60 mmHg for female or SBP < 100 mmHg and DBP < 60 mmHg for male; measured while in a sitting position) will be reviewed by a study physician
- Bradycardia (resting heart rate < 60 bpm) will be reviewed by a study physician
- Subjects are on antihypertensive drugs (e.g., a beta-blocker) that result in hypotension and/or bradycardia as defined above
- Tests positive for illicit drugs, marijuana, or non-prescribed drugs
- Major psychiatric disorders that required hospitalization in the past 6 months such as: major depression, bipolar disorder, schizophrenia, anxiety disorder, or psychotic disorders
- Currently in a treatment program for alcohol or drug abuse, or currently on methadone or buprenorphine (i.e. suboxone, subutex) for treatment of addiction, or currently prescribed stimulants for treatment of ADHD
- History of substance or alcohol abuse (meets DSM IV criteria) per medical record or subject admission
- Subjects are on medications that serve as CYP3A4/5 inhibitors or CYP3A4 inducers including, but are not limited to, valproic acid, macrolide antibiotics, antifungal drugs, St. John wort, ACE inhibitors, nefazodone (antidepressant), calcium channel blockers, H2-receptor antagonists, anti-HIV or AIDS drugs, and antiepileptic drugs
- Subjects are on medications that are ligands for alpha2-adrenergic receptors including antipsychotic drugs (e.g. clozapine) and tricyclic or tetracyclic antidepressants (e.g. imipramine, mirtazapine, mianserin). Any medications taken by a subject at the enrollment will be reviewed regarding their compatibility with guanfacine as well as possible confounding side effects. Subjects will be allowed to take non-opioid pain medications except for gabapentinoids and amitriptyline/nortriptyline as far as such medications do not have incompatibility with guanfacine.
Trial locations and contacts
1 site in 1 country.
United States1 site
MGH Center for Translational Pain Research
Boston, Massachusetts, 02114
About this study
Combination of guanfacine with opioid medication as a standard treatment for chronic pain.
Read the detailed description
This aim proposes that guanfacine would be a useful drug to reverse Opioid-Induced Hyperalgesia (OIH) when combined with opioids in chronic pain management.
- Conditions
- Chronic Pain
- Being tested
- Guanfacine, Placebo
- Keywords
- Pain, Pain management, Neck, Back
- Medical subject headings
- Chronic Pain, Pain, Agnosia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GuanfacineDrug
Also called Tenex, Intuniv
Subjects will be randomized into 1 of the following 3 treatment groups:
- guanfacine (2mg)
- guanfacine (1mg)
- placebo
To compare pain threshold, pain tolerance, and wind up, as measured by QST, throughout 4 weeks of drug treatment (guanfacine or placebo).
PlaceboDrug
Also called Placebo, sugar pill
Subjects will be randomized into 1 of the following 3 treatment groups:
- guanfacine (2mg)
- guanfacine (1mg)
- placebo To compare pain threshold, pain tolerance, and wind up, as measured by QST, throughout 4 weeks of drug treatment (guanfacine or placebo).
| Study group | Role | What they receive |
|---|---|---|
| Guanfacine (2mg) | Active comparator | Subjects will be randomized into 1 of the following 3 treatment groups:
1. guanfacine (2mg)
2. guanfacine (1mg)
3. placebo
Subjects will be instructed to take one capsule in the evening for 4 weeks. Receives: Drug: Guanfacine |
| Guanfacine (1mg) | Active comparator | Subjects will be randomized into 1 of the following 3 treatment groups:
1. guanfacine (2mg)
2. guanfacine (1mg)
3. placebo
Subjects will be instructed to take one capsule in the evening for 4 weeks. Receives: Drug: Guanfacine |
| Placebo | Placebo comparator | Subjects will be randomized into 1 of the following 3 treatment groups:
1. guanfacine (2mg)
2. guanfacine (1mg)
3. placebo
Subjects will be instructed to take one capsule in the evening for 4 weeks. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Numeric Pain Score (0-10: 0 Being no Pain; 10 Being the Worst Pain)
Changes in numeric pain score (as indicated in Outcome Measure Title) will be used to compare the 3 treatment groups.
Measured: baseline and 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2014 (estimated)
- Study startSep 2014
- Primary completionOct 2022
- Study completionOct 2022
Why it stopped: End of NIH funding
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Chronic PainStudies of the same condition, open and under way.
- More trials run by Massachusetts General HospitalThe 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
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- Massachusetts General Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute on Drug Abuse (NIDA)
- Responsible party
- Principal investigator, Jianren Mao, MD, PhD, Massachusetts General Hospital
- Investigators
- Jianren Mao, M.D., Ph.D., Principal investigator, Massachusetts General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02192398
- Sponsor's protocol ID
- 2014P-001377
- Other IDs
- 1R01DA036564-01
- Status last verified
- Jun 2026
- First submitted
- 15 Jul 2014
- Last updated
- 6 Jul 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 6 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Guanfacine on the Reversal of Opioid-induced Hyperalgesia (OIH)
- ClinicalTrials.gov ID
- NCT02192398
- Acronym / sponsor ID
- 2014P-001377
- Conditions
- Chronic Pain
- Keywords
- Pain, Pain management, Neck, Back
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: End of NIH funding
- Enrolment
- 8 participants (actual)
- Lead sponsor
- Massachusetts General HospitalUniversity, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute on Drug Abuse (NIDA)
- Study start
- Sep 2014 (actual)
- Primary completion
- Oct 2022 (actual)
- Study completion
- Oct 2022 (actual)
- First posted
- 16 Jul 2014 (estimated)
- Results
- Posted 6 Jul 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Combination of guanfacine with opioid medication as a standard treatment for chronic pain.
Detailed description
This aim proposes that guanfacine would be a useful drug to reverse Opioid-Induced Hyperalgesia (OIH) when combined with opioids in chronic pain management.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Guanfacine (2mg) | Active comparator | Drug: GuanfacineSubjects will be randomized into 1 of the following 3 treatment groups: 1. guanfacine (2mg) 2. guanfacine (1mg) 3. placebo Subjects will be instructed to take one capsule in the evening for 4 weeks. |
| Guanfacine (1mg) | Active comparator | Drug: GuanfacineSubjects will be randomized into 1 of the following 3 treatment groups: 1. guanfacine (2mg) 2. guanfacine (1mg) 3. placebo Subjects will be instructed to take one capsule in the evening for 4 weeks. |
| Placebo | Placebo comparator | Drug: PlaceboSubjects will be randomized into 1 of the following 3 treatment groups: 1. guanfacine (2mg) 2. guanfacine (1mg) 3. placebo Subjects will be instructed to take one capsule in the evening for 4 weeks. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 18-65 years old
- Chronic neck or back pain condition for at least 6 months
- VAS score of 4-8, despite opioid therapy
- On a stable morphine equivalent dose of at least 60mg/day and ≤ 240mg/day for at least 3 months
Key exclusion criteria (21 listed)
- Has taken Methadone, Suboxone, Fentanyl, and/or Tramadol in the last six (6) months
- Has taken guanfacine (or other alpha-2AR agonists) in the last six (6) months
- Changes to current or adding new pain treatment while enrolled in the study (i.e. opiates, epidural steroid injection) will be reviewed by the study physician
- Unable to independently provide informed written consent
- Sensory deficits at site of QST, such as peripheral neuropathy
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 |
|---|---|---|
| GuanfacineAlso: Tenex, IntunivSubjects will be randomized into 1 of the following 3 treatment groups: 1. guanfacine (2mg) 2. guanfacine (1mg) 3. placebo To compare pain threshold, pain tolerance, and wind up, as measured by QST, throughout 4 weeks of drug treatment (guanfacine or placebo). | Drug | Guanfacine (1mg), Guanfacine (2mg) |
| PlaceboAlso: Placebo, sugar pillSubjects will be randomized into 1 of the following 3 treatment groups: 1. guanfacine (2mg) 2. guanfacine (1mg) 3. placebo To compare pain threshold, pain tolerance, and wind up, as measured by QST, throughout 4 weeks of drug treatment (guanfacine or placebo). | Drug | Placebo |
Primary outcome
Numeric Pain Score (0-10: 0 Being no Pain; 10 Being the Worst Pain)
Time frame: baseline and 4 weeks
Changes in numeric pain score (as indicated in Outcome Measure Title) will be used to compare the 3 treatment groups.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Jul 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- MGH Center for Translational Pain ResearchLink provided by the sponsor.
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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. This study is not recruiting at the moment.
Jianren Mao, M.D., Ph.D. principal investigator
Massachusetts General Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Guanfacine in people with Chronic Pain, run by Massachusetts General Hospital 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 21 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: stopped early, as of the sponsor's last update on 6 Jul 2026. 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?
Yes. Results are posted in the registry (first posted 6 Jul 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Numeric Pain Score (0-10: 0 Being no Pain; 10 Being the Worst Pain) (time frame: baseline and 4 weeks). 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 6 Jul 2026; AzTrials last refreshed its copy on 8 Nov 2026.