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Placebo In Chronic Back Pain (Phase 2)

Brain Mechanisms For Clinical Placebo in Chronic Pain: A Randomized Clinical Trial of Placebo, Active Treatment, and No Treatment in Chronic Back Pain

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02986334
Acronym
PICP2
Enrollment
94
Registered
2016-12-08
Start date
2016-08-31
Completion date
2018-06-30
Last updated
2022-11-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Low Back Pain

Keywords

chronic, low back, back, pain, brain, MRI

Brief summary

This study is designed to examine brain properties for placebo response in chronic back pain patients. The investigators have preliminary data indicating that, in blinded clinical trial studies with neutral instructions regarding treatment, chronic back pain (CBP) patients can be subdivided into placebo responders and non-responders, and these differences are PREDICTABLE a priori, by brain activity. The results imply that CBP placebo may have clinical utility and that its properties can be studied by human brain imaging techniques. In Phase I of the study, the investigators seek to identify brain imaging parameters that predict the propensity for the placebo response in an independent CBP cohort. In Phase II, the investigators will evaluate the interaction between placebo response and medication treatment in individuals stratified as placebo responders versus non-responders. This research is designed to critically assess the neurobiology of placebo analgesia for chronic pain in a partially-blind clinical trial.

Detailed description

Visit 1 (week -3): Screening visit (90 min): Participants will be evaluated with inclusion/exclusion criteria and complete the informed consent documents. A medical/pain history will be taken and physical exam will be completed by a physician and participants will be asked to rate their current back pain intensity. Participants will complete a set of 10 questionnaires that will ask about health and medical history, past and current pain levels, personality, and emotions. Participants will be allowed to take breaks and walk around during this time so that participants don't get tired while filling out questionnaires. Finally, participants will have blood drawn for screening purposes including to see if kidneys and liver are functioning as they should (the investigators will take 40 mL or about 8 teaspoons). Participants will be asked to return in 2 weeks for baseline magnetic resonance imaging (MRI) scans. Participants will be asked to discontinue current pain medications 14 days prior to Visit 2 and take only the rescue medication (rescue medication that is also known as acetaminophen/Tylenol ®), given for pain during this time (see below) - this is so that the investigators can assess baseline amount of pain. Participants will be informed that they may be randomized in the placebo group and/or the no-treatment group (Visit 3) once one qualifies to continue in the study. Participants must, therefore,a be willing and able to stop taking the medication for pain for up to a maximum of 12 weeks during this study. Participants will be given acetaminophen (500 mg, up to 4 times per day) to take for pain relief (as rescue medication), a dose that can be continued throughout the study. Participants are free to stop participation at any point in the study. Participants randomized into the treatment arm may receive the anti-inflammatory drug naproxen, since it is known to increase the risk of stomach and intestinal side effects, a combined naproxen/esomeprazole drug regimen will be given to participants to provide some protection for these types of side effects. Visit 2 (week -1): Baseline Scan (90 min): Participants will rate their pain intensity, complete questionnaires, and undergo brain scanning (anatomical and functional scans). Participants will receive medication, which can be used if the pain becomes too much to handle (500 mg four times per day maximum). The researcher will ask participants about how often participants used the rescue medication and any changes in health they may have experienced since the last visit. Visit 3 (week 0): Start of Treatment Period and Randomization (30-45 min): Participants will rate their pain intensity and complete questionnaires. Participants will be randomized into either a drug (placebo or naproxen and esomeprazole) treatment group or no treatment group; if participants are assigned to a treatment group (active or placebo), neither participants nor the clinical coordinator/assistant will know which group participants are allocated in. Enough medication will be given to participants to last until the next visit. The placebo group will receive two placebo capsules twice daily and the active drug group will receive one naproxen capsule (500mg) and one esomeprazole capsule (20mg) twice daily (morning and night) for the treatment period. The medication (Naproxen or Placebo) needs to be taken with at least one full glass (8 oz) of water and the other medication (Esomeprazole or Placebo) should be taken one hour before a meal. The researcher will provide the study medication; if participants were randomized into the no treatment group, participants will only receive rescue medication. The researcher will ask participants about how often participants used the rescue medication and any side effects participants experienced since Visit 2 took place. Additional rescue medication will be given. Visit 4 (week 3): Continuing Assessment (30-45 min). The procedures described for Visit 3 will be repeated during this visit. The researcher will ask participants about how often they used the rescue medication and any side effects experienced since Visit 3 took place. As well, the researcher will ask how often participants took the study medication (if in a treatment group) and document the total pills ingested. Visit 5 (week 6): End of Treatment/Start of Washout and Final Scan (60-90 min): The procedures described for Visit 2 will be repeated during this visit. The researcher will ask participants about how often and reliably participants took the medication (if in a treatment group), as well as how often they used the rescue medication and any side effects experienced since Visit 4 took place. Participants will only receive the rescue medication for the upcoming 3 weeks. Visit 6 (week 9): Final Visit/End of Washout (30-45 min): Participants will return to complete questionnaires, but no brain scans will be done. The researcher will ask participants about how often they used the rescue medication and any side effects experienced since Visit 5 took place. If participants are in one of the treatment groups, participants will be asked to return all of the study medication and rescue medication at this time, and all treatment will be stopped at this visit.

Interventions

DRUGNaproxen

Subjects enrolled in the active treatment arm will receive 500mg of Naproxen prescribed twice daily, once in the morning and evening.

DRUGOmeprazole

Subjects enrolled in the active treatment arm will receive 20mg of Omeprazole prescribed twice daily, once in the morning and evening. Furthermore, subjects should take this one hour before a meal.

DRUGPlacebo

Subjects enrolled in the inactive treatment arm will receive two prescriptions, however, there are no active ingredients and are intended to look identical to the active treatment. Therefore, subjects will be instructed exactly the same way as if they were ingesting the active treatment.

Sponsors

National Center for Complementary and Integrative Health (NCCIH)
CollaboratorNIH
National Institutes of Health (NIH)
CollaboratorNIH
Apkar Apkarian
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* History of low back pain for a minimum of 6 months with or without signs and symptoms of radiculopathy * Male or female, between the ages of 18 and 75 years, with no racial or ethnic restrictions * Must have a Visual Analog Scale (VAS) pain score of 5 mm (of 10 mm maximum) at the screening visit (for which 0mm = no pain, and 10 mm = worst pain imaginable); * Must be able to read and speak English and be willing to read and understand instructions as well as questionnaires; * Must be in generally stable health; * Must sign an informed consent document after a complete explanation of the study documenting that they understand the purpose of the study, procedures to be undertaken, possible benefits, potential risks, and are willing to participate * Must have, on average, 5/10 units (VAS scale) of pain over the course of a two-week period prior to visit 1; rounding up from 4.5/10 is permissible. * Must be willing to complete daily smart phone/computer app ratings.

Exclusion criteria

* Low back pain associated with any systemic signs or symptoms, e.g., fever, chills; * Evidence of rheumatoid arthritis, ankylosing spondylitis, acute vertebral fractures, fibromyalgia, history of tumor in the back; * Other comorbid chronic pain or neurological conditions; * Involvement in litigation regarding their back pain or having a disability claim or receiving workman's compensation or seeking either as a result of their low back pain; * Diagnosis of current depression or psychiatric disorder requiring treatment, or such a diagnosis in the previous 6 months; * Beck Depression Inventory (BDI) Ia score greater or equal to 19 for two consecutive completions; if the first score meets this criteria, the participant must be re-tested before his/her next visit, but if the second score does not meet this criteria, the participant will be included and followed closely throughout the study * Use of therapeutic doses of antidepressant medications (i.e., tricyclic depressants, SSRIs, SNRIs; low doses used for sleep may be allowed); * Significant other medical disease such as unstable diabetes mellitus, congestive heart failure, coronary or peripheral vascular disease, chronic obstructive lung disease, or malignancy; * History of gastrointestinal ulcer during the past year; * History of myocardial infarction in the past year; * Uncontrolled hypertension; * Renal insufficiency; * Allergic to, or non-tolerant of, NSAIDs; * History of aspirin-sensitive asthma; * Current use of recreational drugs or history of alcohol or drug abuse; * Any change in medication for back pain in the last 30 days only applicable for visit 1 * High dose opioid prophylaxis, as defined as \> 50mg morphine equivalent/day; * Any medical condition that in the investigator's judgment may prevent the individual from completing the study or put the individual at undue risk; * In the judgment of the investigator, unable or unwilling to follow protocol and instructions; * Evidence of poor treatment compliance, in the judgment of the investigator; * Intra-axial implants (e.g. spinal cord stimulators or pumps); * All

Design outcomes

Primary

MeasureTime frameDescription
Percent Change in Pain Assessed by Visual Analogue Scale (VAS)12 weeksSelf-report pain using a VAS scale (0-10) : 0 represents no pain and 10 the worst imaginable pain. Results are presented as percentage (%) change in pain before and after the intervention (baseline and post-intervention, 12 weeks). Percentage change is calculated with post-intervention pain minus baseline pain, divided by baseline pain i.e. (post - baseline) / baseline.

Countries

United States

Participant flow

Participants by arm

ArmCount
No Treatment Intervention
Observational Subjects randomized to this arm will be asked to discontinue their current pain medications for the length of the study. This arm is not blinded, as both study staff and participants will be aware that they are not receiving a study treatment.
14
Active Treatment Intervention
Naproxen & Omeprazole Subjects randomized to this arm will be asked to discontinue their current pain medications and take one 500mg naproxen capsule and one 40mg omeprazole capsule twice a day for the length of the study. This arm is double-blind, as neither participants nor study staff will know what medication the participants is receiving (blind to active versus placebo treatment). Naproxen: Subjects enrolled in the active treatment arm will receive 500mg of Naproxen prescribed twice daily, once in the morning and evening. Omeprazole: Subjects enrolled in the active treatment arm will receive 20mg of Omeprazole prescribed twice daily, once in the morning and evening. Furthermore, subjects should take this one hour before a meal.
40
Placebo Treatment Intervention
Subjects randomized to this arm will be asked to discontinue their current pain medications and take two placebo capsules twice a day for the length of the study. This arm is double-blind, as neither participants nor study staff will know what medication the participants is receiving (blind to active versus placebo treatment) Placebo: Subjects enrolled in the inactive treatment arm will receive two prescriptions, however, there are no active ingredients and are intended to look identical to the active treatment. Therefore, subjects will be instructed exactly the same way as if they were ingesting the active treatment.
40
Total94

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall StudyAdverse Event021
Overall StudyLost to Follow-up121
Overall Studynon compliance in phone ratings212
Overall Studyundisclosed comorbidities011
Overall StudyWithdrawal by Subject012

Baseline characteristics

CharacteristicActive Treatment InterventionPlacebo Treatment InterventionTotalNo Treatment Intervention
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
9 Participants7 Participants19 Participants3 Participants
Age, Categorical
Between 18 and 65 years
31 Participants33 Participants75 Participants11 Participants
Age, Continuous58.0 years
STANDARD_DEVIATION 10.5
53.0 years
STANDARD_DEVIATION 14.3
55.8 years
STANDARD_DEVIATION 12.5
59.6 years
STANDARD_DEVIATION 11.6
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants1 Participants1 Participants0 Participants
Race (NIH/OMB)
Black or African American
23 Participants25 Participants56 Participants8 Participants
Race (NIH/OMB)
More than one race
0 Participants3 Participants5 Participants2 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants2 Participants3 Participants0 Participants
Race (NIH/OMB)
White
16 Participants9 Participants29 Participants4 Participants
Region of Enrollment
United States
40 participants40 participants94 participants14 participants
Sex: Female, Male
Female
23 Participants17 Participants49 Participants9 Participants
Sex: Female, Male
Male
17 Participants23 Participants45 Participants5 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
0 / 141 / 400 / 40
other
Total, other adverse events
9 / 1416 / 4020 / 40
serious
Total, serious adverse events
0 / 140 / 400 / 40

Outcome results

Primary

Percent Change in Pain Assessed by Visual Analogue Scale (VAS)

Self-report pain using a VAS scale (0-10) : 0 represents no pain and 10 the worst imaginable pain. Results are presented as percentage (%) change in pain before and after the intervention (baseline and post-intervention, 12 weeks). Percentage change is calculated with post-intervention pain minus baseline pain, divided by baseline pain i.e. (post - baseline) / baseline.

Time frame: 12 weeks

ArmMeasureValue (MEAN)Dispersion
No Treatment InterventionPercent Change in Pain Assessed by Visual Analogue Scale (VAS)-0.0145 percentage of pain changeStandard Error 0.036
Active Treatment InterventionPercent Change in Pain Assessed by Visual Analogue Scale (VAS)-0.2082 percentage of pain changeStandard Error 0.048
Placebo Treatment InterventionPercent Change in Pain Assessed by Visual Analogue Scale (VAS)-0.1109 percentage of pain changeStandard Error 0.05

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026