The Effect of Oxytocin on Placebo Analgesia: an Experimental Study in Healthy Volunteers

Study Overview
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Brief Summary
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Placebo responses contribute to medical treatment outcome. The purpose of this study is to determine whether a single intranasal application of oxytocin can increase the placebo response in an experimental model of placebo analgesia in healthy volunteers.

Detailed Description
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Placebo responses contribute to medical treatment outcome. The purpose of this study is to determine whether a single intranasal application of oxytocin can increase the placebo response in an experimental model of placebo analgesia in healthy volunteers. The rationale to study the effects of oxytocin on placebo analgesia is based on previous studies showing that oxytocin fosters processes such as empathy, trust and social learning, which are key elements of the patient-physician relationship that is pivotal to placebo responses. In this experimental mechanisms study we used oxytocin as a tool to modulate these factors. Placebo analgesia is induced verbal instruction. Therefore two identically looking placebo ointments were applied to two sites of the participants' volar forearm. The ointments were introduced as a local anesthetic that could reduce or even abolish pain (placebo) and a control cream (control), respectively.

Official Title
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The Effect of Oxytocin on Placebo Analgesia: an Experimental Study in Healthy Volunteers Using a Double-blind Design

Conditions
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Mechanisms and Modulators of Placebo Analgesia in Healthy Volunteers

Intervention / Treatment
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* Drug: Oxytocin
* Other: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy volunteers, male and female being German-speaking Agreeing to participate, verified by completion of informed consent Exclusion Criteria: acute or chronic pain condition use of any concomitant medication except contraceptives currently pregnant (verified by urine pregnancy test) or lactating major mental disorder Inability to comply with the study procedures abnormal pain sensitivity as indicated by pain threshold alcohol intake within last 24 hours

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: oxytocin<br>application of intranasal oxytocin 40IE | Drug: Oxytocin<br> <br> |
| Placebo Comparator: placebo<br>application of intranasal saline Both sprays (saline/oxytocin) are delivered in identical containers manufactured by the University pharmacy to assure blinding. | Other: placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Placebo analgesic responses | In this study the placebo analgesic response is defined as the difference in pain rating (visual analogue scale [0-100]) to thermal painful stimulation on the forearm on the placebo site compared to a control site. |   45 min after appliction of oxytocin or saline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pain rating on the control site | VAS pain rating [0-100] in the control (non-placebo) condition. |  45 min after application | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pain, pain modulation, placebo analgesia