Placebo EffectNCT00426010
Measuring Placebo Effect by Elimination and Investigating Mechanism of Action
A study of Placebo Effect and Placebo Mechanisms of Action, run by King Faisal Specialist Hospital & Research Center at 1 site in Saudi Arabia.
Trial summary
We propose to measure the effect of placebo by elimination as well as by a "balanced placebo" design, determine its interaction with active drug, and explore whether placebo exerts part of its effect at the pharmacokinetics level. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Placebo Effect, Placebo Mechanisms of Action
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 180 participants
- Where
- 1 siteSaudi Arabia
- Study dates
- Jan 2007to Feb 2009
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Males and nonpregnant females 18 and 40 years of age with at least high school education.
Who cannot join
- Include evidence of clinically relevant deviation from normal health (such that it may affect the endpoints, make the ingestion of caffeine dangerous, or affect the pharmacokinetics/pharmacodynamics of caffeine),
- Pregnancy,
- Poor venous access,
- Hypertension (more than 140/90),
- Heart disease,
- History of panic attacks,
Show all 12Show fewer
- Average daily caffeine consumption of more than 300 or less than 100 mg,
- Smoking,
- Alcohol abuse,
- Taking any medication other than birth control bills (including over-the-counter drugs) within one week from starting the study,
- Hypersensitivity to caffeine or related compounds,
- Hemoglobin of less than 13 gm/L, and recent (one week) acute illness
Trial locations and contacts
1 site in 1 country.
Saudi Arabia1 site
Center for Clinical Studies & Empirical Ethics, KFSH & RC
Riyadh, 11211
About this study
Official title: Measuring Placebo Effect by Elimination and Investigating Its Mechanism of Action
We propose to measure the effect of placebo by elimination as well as by a "balanced placebo" design, determine its interaction with active drug, and explore whether placebo exerts part of its effect at the pharmacokinetics level.
Read the detailed description
Placebos have been in use for centuries in medical practice. However, there is continued controversy regarding their effectiveness and mechanisms of action.
The results of the study are expected to further our understanding of a widely used medical intervention, i.e., placebo, and of how to maximize its potential beneficial effect. It will also help assess the appropriateness of measuring the placebo effect by elimination, which has important ethical implications in relation to the design of randomized clinical trials.
Comparison: caffeine vs placebo. Dependent variables:4 hours area under the curve (AUC) of pharmacodynamics endpoints as well as pharmacokinetics endpoints in a subgroup.
- Conditions
- Placebo Effect, Placebo Mechanisms of Action
- Being tested
- caffeine/placebo
- Keywords
- Placebo effect, Caffeine, Systolic BP, VAS
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
caffeine/placeboDrug
caffeine or placebo, either overt or covert
| Study group | Role | What they receive |
|---|---|---|
| 1 | Active comparator | overt then covert caffeine Receives: Drug: caffeine/placebo |
| 2 | Active comparator | covert then overt caffeine Receives: Drug: caffeine/placebo |
| 3 | Active comparator | overt then covert placebo Receives: Drug: caffeine/placebo |
| 4 | Active comparator | covert then overt placebo Receives: Drug: caffeine/placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
4 hours area under the curve (AUC) of peripheral systolic blood pressure
Measured: 4 hours
4 hours area under the curve (AUC) of energy level measured by Visual Analogue Scales.
Measured: 4 hours
4 hours area under the curve (AUC) of alertness level measured by Visual Analogue Scales.
Measured: 4 hours
4 hours area under the curve (AUC) of nausea measured by Visual Analogue Scales.
Measured: 4 hours
Secondary outcomes (4)
Cmax of serum caffeine (in a subgroup)
Measured: 4 hours
Tmax of serum caffeine (in a subgroup)
Measured: 4 hours
t1/2 of serum caffeine (in a subgroup)
Measured: 14 hours
AUC of serum caffeine (in a subgroup)
Measured: 14 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jan 2007 (estimated)
- Study startJan 2007
- Primary completionFeb 2009
- Study completionFeb 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Placebo EffectStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- King Faisal Specialist Hospital & Research Center
- Sponsor type
- University, hospital or other
- Collaborators
- King AbdulAziz City for Science and Technology
- Investigators
- Muhammad M Hammami, MD, PhD, Principal investigator, KFSH & RC, Riyadh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00426010
- Sponsor's protocol ID
- RAC# 2051072
- Other IDs
- KACST:ARP-26-45
- Status last verified
- Dec 2011
- First submitted
- 23 Jan 2007
- Last updated
- 13 Dec 2011
- Results posted
- No
Publications
Hammami MM, Al-Gaai EA, Alvi S, Hammami MB. Interaction between drug and placebo effects: a cross-over balanced placebo design trial. Trials. 2010 Nov 19;11:110. doi: 10.1186/1745-6215-11-110.
PubMed 21092089
Study at a glance
From the registry record, last updated by the sponsor on 13 Dec 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measuring Placebo Effect by Elimination and Investigating Its Mechanism of Action
- ClinicalTrials.gov ID
- NCT00426010
- Acronym / sponsor ID
- RAC# 2051072
- Conditions
- Placebo Effect, Placebo Mechanisms of Action
- Keywords
- Placebo effect, Caffeine, Systolic BP, VAS
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- King Faisal Specialist Hospital & Research CenterUniversity, hospital or other
- Collaborators
- King AbdulAziz City for Science and Technology
- Study start
- Jan 2007
- Primary completion
- Feb 2009 (actual)
- Study completion
- Feb 2009 (actual)
- First posted
- 24 Jan 2007 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
We propose to measure the effect of placebo by elimination as well as by a "balanced placebo" design, determine its interaction with active drug, and explore whether placebo exerts part of its effect at the pharmacokinetics level.
Detailed description
Placebos have been in use for centuries in medical practice. However, there is continued controversy regarding their effectiveness and mechanisms of action.
The results of the study are expected to further our understanding of a widely used medical intervention, i.e., placebo, and of how to maximize its potential beneficial effect. It will also help assess the appropriateness of measuring the placebo effect by elimination, which has important ethical implications in relation to the design of randomized clinical trials.
Comparison: caffeine vs placebo. Dependent variables:4 hours area under the curve (AUC) of pharmacodynamics endpoints as well as pharmacokinetics endpoints in a subgroup.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 1 | Active comparator | Drug: caffeine/placeboovert then covert caffeine |
| 2 | Active comparator | Drug: caffeine/placebocovert then overt caffeine |
| 3 | Active comparator | Drug: caffeine/placeboovert then covert placebo |
| 4 | Active comparator | Drug: caffeine/placebocovert then overt placebo |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Males and nonpregnant females 18 and 40 years of age with at least high school education.
Key exclusion criteria (12 listed)
- Include evidence of clinically relevant deviation from normal health (such that it may affect the endpoints, make the ingestion of caffeine dangerous, or affect the pharmacokinetics/pharmacodynamics of caffeine),
- Pregnancy,
- Poor venous access,
- Hypertension (more than 140/90),
- Heart disease,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| caffeine/placebocaffeine or placebo, either overt or covert | Drug | 1, 2, 3, 4 |
Primary outcome
4 hours area under the curve (AUC) of peripheral systolic blood pressure
Time frame: 4 hours
4 hours area under the curve (AUC) of energy level measured by Visual Analogue Scales.
Time frame: 4 hours
4 hours area under the curve (AUC) of alertness level measured by Visual Analogue Scales.
Time frame: 4 hours
4 hours area under the curve (AUC) of nausea measured by Visual Analogue Scales.
Time frame: 4 hours
4 secondary outcomes
Cmax of serum caffeine (in a subgroup)
Time frame: 4 hours
Tmax of serum caffeine (in a subgroup)
Time frame: 4 hours
t1/2 of serum caffeine (in a subgroup)
Time frame: 14 hours
AUC of serum caffeine (in a subgroup)
Time frame: 14 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Dec 2011.
- Derived from this study: PubMed 21092089Hammami MM, Al-Gaai EA, Alvi S, Hammami MB. Interaction between drug and placebo effects: a cross-over balanced placebo design trial. Trials. 2010 Nov 19;11:110. doi: 10.1186/1745-6215-11-110.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Muhammad M Hammami, MD, PhD principal investigator
KFSH & RC, Riyadh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study of Placebo Effect and Placebo Mechanisms of Action, run by King Faisal Specialist Hospital & Research Center at 1 site in Saudi Arabia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Dec 2011. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Saudi Arabia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
4 hours area under the curve (AUC) of peripheral systolic blood pressure (time frame: 4 hours). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00426010, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Dec 2011; AzTrials last refreshed its copy on 8 Nov 2026.