Boosting Open-Label Placebo Effects in Acute Induced Pain in Healthy Adults
- Conditions
- Acute Pain
- Interventions
- Procedure: OLP-injectionOther: Scripted Evidence-based treatment rationaleOther: Experimental model of acute pain
- Registration Number
- NCT05819476
- Lead Sponsor
- University Hospital, Basel, Switzerland
- Brief Summary
This study is to investigate the effect of open-label placebo (OLP) application on acute pain in an experimental model of acute pain (simulating wound pain: this installation will apply monophasic, rectangular electrical pulses of 0.5ms duration with alternating polarity at 2 Hz frequency. The current will be increased to target a pain rating of 6 of 10 on the NRS (0 = no pain, 10 = worst imaginable pain). Three further adjustments in current will be made every 5 minutes for the next 15 minutes to compensate for habituation. This final current will be kept constant until the end of the particular experiment).
In Part 1 duration of OLP analgesia will be examined, and onset and size of the effect will be reevaluated.
In Part 2 of this study outcomes between subjects receiving one OLP injection, subjects receiving one repetition of the injection on a fixed time point and subjects receiving one repetition of the injection on-demand will be evaluated
- Detailed Description
Pain is highly prevalent in hospital settings. Standard systemic treatment for acute pain consists mainly of basic analgesia. The use of these drugs is often restricted due to their contraindications. Placebo is used nowadays to describe sham treatments and "inert" substances like sugar pills and saline injections. Placebos are proven to elicit clinically significant effects in various conditions, including pain. Ethical concerns about the use of deceptive placebos have prevented their implementation in clinical practice. A possibility to address this issue would be to prescribe placebos openly, that means, without deception. This randomized crossover study evaluates the efficacy of open-label placebo (OLP) in acute pain. Subjective pain ratings and areas of hyperalgesia and allodynia will be measured in a well-established experimental pain model (intradermal electrical stimulation model evoking pain: this installation will apply monophasic, rectangular electrical pulses of 0.5ms duration with alternating polarity at 2 Hz frequency. The current will be increased to target a pain rating of 6 of 10 on the NRS (0 = no pain, 10 = worst imaginable pain). Three further adjustments in current will be made every 5 minutes for the next 15 minutes to compensate for habituation. This final current will be kept constant until the end of the particular experiment) and analgesia elicited by OLP injections will be investigated.
In Part 1 duration of OLP analgesia will be examined, and onset and size of the effect will be reevaluated.
In Part 2 of this study outcomes between subjects receiving one OLP injection, subjects receiving one repetition of the injection on a fixed time point and subjects receiving one repetition of the injection on-demand will be evaluated (which leaves the last group a choice over when they would like to have the placebo "booster").
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 141
- Healthy volunteers (ASA Class I or II), aged 18 to 65 years
- BMI between 18 and 25kg/m2
- Able to understand the study and the NRS
- Able to give informed consent
- Participation in a previous open-label placebo study; for Part 2, this includes Part 1 of this study
- Regular intake of medications or drugs potentially interfering with pain sensation (analgesics, opioids, antihistamines, calcium and potassium channel blockers, serotonin/ noradrenaline reuptake inhibitors, corticosteroids)
- Neuropathy
- Chronic pain
- Neuromuscular disease
- Dermatological disease (i.e. Atopic Dermatitis)
- Psychiatric disease
- Pregnancy / Lactation
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Part 2/ Group B: 2x OLP; booster time fixed Scripted Evidence-based treatment rationale In Part 2, Group B participants will receive two injections, the first at twenty minutes after start of the experiment, and the second at a time point derived from Part 1 (if data is inconclusive; at 100 minutes). For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain. Part 1: Visit 1 (OLP intervention) followed by Visit 2 (No treatment) OLP-injection In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 1. Visit 2 (No treatment) will be the control of the study intervention. Part 1: Visit 1 (OLP intervention) followed by Visit 2 (No treatment) Scripted Evidence-based treatment rationale In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 1. Visit 2 (No treatment) will be the control of the study intervention. Part 2/ Group A: 1x OLP (Control) OLP-injection In Part 2, the Group A (Control) receives just one single OLP injection and no repetition. Part 2/ Group A: 1x OLP (Control) Scripted Evidence-based treatment rationale In Part 2, the Group A (Control) receives just one single OLP injection and no repetition. Part 2/ Group B: 2x OLP; booster time fixed OLP-injection In Part 2, Group B participants will receive two injections, the first at twenty minutes after start of the experiment, and the second at a time point derived from Part 1 (if data is inconclusive; at 100 minutes). For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain. Part 2/ Group C: 2x OLP; booster on- demand OLP-injection In Part 2, Group C participants will receive two injections, the first at twenty minutes after start of the experiment, and the second on demand. For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain. Part 1: Visit 1 (No treatment) followed by Visit 2 (OLP intervention) OLP-injection In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 2. Visit 1 (No treatment) will be the control of the study intervention. Part 1: Visit 1 (No treatment) followed by Visit 2 (OLP intervention) Scripted Evidence-based treatment rationale In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 2. Visit 1 (No treatment) will be the control of the study intervention. Part 2/ Group C: 2x OLP; booster on- demand Scripted Evidence-based treatment rationale In Part 2, Group C participants will receive two injections, the first at twenty minutes after start of the experiment, and the second on demand. For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain. Part 1: Visit 1 (No treatment) followed by Visit 2 (OLP intervention) Experimental model of acute pain In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 2. Visit 1 (No treatment) will be the control of the study intervention. Part 1: Visit 1 (OLP intervention) followed by Visit 2 (No treatment) Experimental model of acute pain In Part 1, participants will receive one injection (administration of open-label placebo injections without any active ingredient (5 ml 0.9% saline)) at twenty minutes after start of the experiment during the intervention visit 1. Visit 2 (No treatment) will be the control of the study intervention. Part 2/ Group A: 1x OLP (Control) Experimental model of acute pain In Part 2, the Group A (Control) receives just one single OLP injection and no repetition. Part 2/ Group B: 2x OLP; booster time fixed Experimental model of acute pain In Part 2, Group B participants will receive two injections, the first at twenty minutes after start of the experiment, and the second at a time point derived from Part 1 (if data is inconclusive; at 100 minutes). For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain. Part 2/ Group C: 2x OLP; booster on- demand Experimental model of acute pain In Part 2, Group C participants will receive two injections, the first at twenty minutes after start of the experiment, and the second on demand. For every subsequent OLP administration, patients will be reminded of the inertness of the injection and that this injection might help with regulating pain.
- Primary Outcome Measures
Name Time Method Part 2: Change in Area under the Pain Curve (AUPC) During three hours after administering an OLP Area under the Pain Curve (AUPC) using the numeric rating scale (NRS; 0 = no pain, 10 = worst imaginable pain). Comparison of the AUPCs of subjects receiving just one OLP injection with subjects additionally receiving one repetition of OLP administration at a time point derived from Part 1 and subjects getting the second OLP injection on-demand.
Part 1: Change in Area under the Pain Curve (AUPC) During three hours after administering an OLP Area under the Pain Curve (AUPC) using the numeric rating scale (NRS; 0 = no pain, 10 = worst imaginable pain) during three hours after administering an OLP
- Secondary Outcome Measures
Name Time Method Part 1 and 2: Change in Area under the Curve (AUC) of area of hyperalgesia Up to 200 minutes after electrical pain stimulation Change in Area under the Curve (AUC) of area of hyperalgesia comparing the intervention and control (no treatment) visit. Pinprick hyperalgesia will be assessed every 10 minutes after OLP administration) using a 600 millinewton (mN) von Frey filament.
Part 1 and 2: Change in subjective pain ratings on each measurement point using the numeric rating scale (NRS) Up to 200 minutes after electrical pain stimulation Change in subjective pain ratings on each measurement point using the numeric rating scale (NRS); NRS; 0 = no pain, 10 = worst imaginable pain) every five minutes after OLP administration)
Part 1 and 2: Change in Area under the Curve (AUC) of area of allodynia Up to 200 minutes after electrical pain stimulation Change in Area under the Curve (AUC) of area of allodynia comparing the intervention and control (no treatment) visit. Allodynia will be determined using a dry cotton swab every 10 minutes after OLP administration).
Trial Locations
- Locations (1)
University Hospital of Basel (USB); Department of Anaesthesiology
🇨🇭Basel, Switzerland