Boosting Open-Label Placebo Effects in Acute Induced Pain in Healthy Adults

Acute Pain Clinical Trial

— BOLPAP  

Official title:

Boosting Open-Label Placebo Effects in Acute Induced Pain in Healthy Adults

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05819476
• Other study ID #: 2023-00296; am23Schneider
• Status: Recruiting
• Phase: N/A
• Start date: March 23, 2023
• Est. completion date: April 2024

Study information

• Verified date: November 2023
• Source: University Hospital, Basel, Switzerland
• Contact: Tobias Schneider, MD
• Phone: +41 61 328 65 43
• Email: tobias.schneider[@]usb.ch
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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

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 information / eligibility

• Status: Recruiting
• Enrollment: 141
• Est. completion date: April 2024
• Est. primary completion date: April 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Acute Pain

Intervention

Procedure:
• OLP-injection
Open-label placebo injections without any active ingredient (5 ml 0.9% saline). All participants will be informed that the administered injections are placebo infusions.

Other:
• Scripted Evidence-based treatment rationale
As a second component the intervention will consist of an evidence-based treatment rationale, which will be delivered to patients receiving the intervention prior to the OLP-injections, explaining placebo analgesia in pain in general and specifically in OLP. In the context of OLP treatments this rationale is important in order to create a mental state of positive expectations.
• Experimental model of acute pain
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).

Locations

Country	Name	City	State
Switzerland	University Hospital of Basel (USB); Department of Anaesthesiology	Basel

Sponsors (1)

Lead Sponsor	Collaborator
University Hospital, Basel, Switzerland

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Part 1: Change in Area under the Pain Curve (AUPC)	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	During three hours after administering an OLP
Primary	Part 2: Change in Area under the Pain Curve (AUPC)	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.	During three hours after administering an OLP
Secondary	Part 1 and 2: Change in subjective pain ratings on each measurement point using the numeric rating scale (NRS)	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)	Up to 200 minutes after electrical pain stimulation
Secondary	Part 1 and 2: Change in Area under the Curve (AUC) of area of hyperalgesia	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.	Up to 200 minutes after electrical pain stimulation
Secondary	Part 1 and 2: Change in Area under the Curve (AUC) of area of allodynia	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).	Up to 200 minutes after electrical pain stimulation