An interventional study of Relistor Injectable Product in Chronic Widespread Pain, sponsored by Florida International University. Recruiting at 1 site in United States. Open to participants aged 19 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-11.
Sponsored by Florida International University · Not applicable, Interventional, and Basic science
To determine if decreased production or release of endogenous opioid peptides by peripheral immune cells contributes to hypersensitivity in people with HIV
The prevalence of chronic widespread pain (CWP) in individuals infected with the human immunodeficiency virus (HIV-1) includes regional and widespread musculoskeletal pain of neuropathic and inflammatory nature. HIV-related CWP leads to 10x greater odds of functional impairment. However, the specific mechanisms that contribute to CWP in HIV are not understood. Thus, pharmacological and non-pharmacological approaches to mitigate CWP have had minimal benefits, contributing to an overreliance on opioids and alarming rise in addiction and overdose. The overall objective of this study is to address the gap in the knowledge of the pathogenesis of HIV-related CWP. Specifically, the role of impaired endogenous opioid synthesis/release from leukocytes in people with HIV (PWH) who self-report CWP will be explored. Leukocytes (neutrophils, monocytes/macrophages, and lymphocytes) are a rich source of opioid peptides (Met-enkephalin, dynorphin A, β-endorphin) that inhibit nociception by binding to peripheral opioid receptors. Therefore, to establish whether decreased peripheral opioid peptides correlate with experimental pain measures in PWH with self-reported CWP, quantitative sensory testing (QST) will be completed before and after administration of methylnaltrexone bromide (RELISTOR), a clinically available, peripherally acting opioid receptor antagonist.
3,227 studies on the registry are indexed under Chronic Pain; 729 are open to participants now.
This study's planned enrollment of 200 is above the median of 60 across 2,388 interventional studies indexed under Chronic Pain.
Browse Chronic Pain studies →Florida International University is the lead sponsor of 104 studies on the registry; 20 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
50 Participants will be randomly administered saline or RELISTOR (Individuals weighing 38-\<62 kg will receive an 8 mg dose; those weighing 62-114 kg will receive a 12 mg dose; Participants weighing more than 114 kg will receive 0.15 mg/kg) in counterbalance between visit 1 and visit 2.
Drug: Relistor Injectable Product
50 Participants will be randomly administered saline or RELISTOR (Individuals weighing 38-\<62 kg will receive an 8 mg dose; those weighing 62-114 kg will receive a 12 mg dose; Participants weighing more than 114 kg will receive 0.15 mg/kg) in counterbalance between visit 1 and visit 2.
Drug: Relistor Injectable Product
50 Participants will be randomly administered saline or RELISTOR (Individuals weighing 38-\<62 kg will receive an 8 mg dose; those weighing 62-114 kg will receive a 12 mg dose; Participants weighing more than 114 kg will receive 0.15 mg/kg) in counterbalance between visit 1 and visit 2.
Drug: Relistor Injectable Product
50 Participants will be randomly administered saline or RELISTOR (Individuals weighing 38-\<62 kg will receive an 8 mg dose; those weighing 62-114 kg will receive a 12 mg dose; Participants weighing more than 114 kg will receive 0.15 mg/kg) in counterbalance between visit 1 and visit 2.
Drug: Relistor Injectable Product
Relistor is a peripherally acting opioid receptor antagonist approved by the FDA for relief of opioid-induced constipation
Also known as: Methylnaltrexone Bromide
Quantitative sensory testing (QST)
Measured at baseline and 30 min post intervention to assess change in response. (0=no pain, 100=most pain) * Heat Pain - 1) A slowly increasing heat stimulus (44°C, 46°C, and 48°C) will be delivered; 2) a series of 5 heat pulses (about 2 sec) will be given and pain will be rated (0-100) * Touch Test Pain. Von Frey filament will be tapped on knee and hand and asked to rate the pain (0-100) after a single tap, and after 10 consecutive taps * Pressure Pain Threshold. A slowly increasing pressure will be applied on forearm and shoulder with a probe (Algomed) till pain is felt. Then constant pressure will be applied till the sensation first becomes painful to assess threshold in kilopascals * Combined Pressure and Cold Pain. Hand will be immersed in cold water (10°C). After 30 sec, pain intensity will be rated (0-100). Hand will be kept in cold water for another 30 sec and then the pressure pain test will be performed, and first instance of pain due to pressure will be assessed
Time frame: At baseline (study visit 1)
Quantitative sensory testing (QST)
Measured at baseline and 30 min post intervention to assess change in response. (0=no pain, 100=most pain) * Heat Pain - 1) A slowly increasing heat stimulus (44°C, 46°C, and 48°C) will be delivered; 2) a series of 5 heat pulses (about 2 sec) will be given and pain will be rated (0-100) * Touch Test Pain. Von Frey filament will be tapped on knee and hand and asked to rate the pain (0-100) after a single tap, and after 10 consecutive taps * Pressure Pain Threshold. A slowly increasing pressure will be applied on forearm and shoulder with a probe (Algomed) till pain is felt. Then constant pressure will be applied till the sensation first becomes painful to assess threshold in kilopascals * Combined Pressure and Cold Pain. Hand will be immersed in cold water (10°C). After 30 sec, pain intensity will be rated (0-100). Hand will be kept in cold water for another 30 sec and then the pressure pain test will be performed, and first instance of pain due to pressure will be assessed
Time frame: Study visit 2 will occur at least 5-7 days after the first visit
McGill Pain Questionnaire-Short Form
15 descriptors (11 sensory; 4 affective) using an intensity scaled ranging from 0-3 on pain scale (0 = no pain, 1 = mild pain, 2 = moderate pain or 3 = severe pain)
Time frame: At baseline (study visit 1)
McGill Pain Questionnaire-Short Form
15 descriptors (11 sensory; 4 affective) using an intensity scaled ranging from 0-3 on pain scale (0 = no pain, 1 = mild pain, 2 = moderate pain or 3 = severe pain)
Time frame: Study visit 2 will occur at least 5-7 days after the first visit
Measuring endogenous opioid peptides in plasma and peripheral leukocytes
20 ml blood will be drawn to isolate plasma and peripheral leukocytes
Time frame: At baseline (study visit 1)
Started Nov 2021 (actual). Primary completion is estimated for May 2027, 66 months after the start.
Of 1,295 non-industry interventional studies with no phase under Chronic Pain, half reached primary completion within 20 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 39. This study's planned 66 months is above that.
Counting every sponsor, half of 1,378 studies reached it within 20 months; a quarter within 9 and three quarters within 38.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Methylnaltrexone
Florida International University →