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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.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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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

Other trials in Saudi Arabia

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.

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 groups in NCT00426010
Study groupRoleWhat they receive
1Active comparatorovert then covert caffeine
Receives: Drug: caffeine/placebo
2Active comparatorcovert then overt caffeine
Receives: Drug: caffeine/placebo
3Active comparatorovert then covert placebo
Receives: Drug: caffeine/placebo
4Active comparatorcovert then overt placebo
Receives: Drug: caffeine/placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 4 hours area under the curve (AUC) of peripheral systolic blood pressure

    Measured: 4 hours

  2. 4 hours area under the curve (AUC) of energy level measured by Visual Analogue Scales.

    Measured: 4 hours

  3. 4 hours area under the curve (AUC) of alertness level measured by Visual Analogue Scales.

    Measured: 4 hours

  4. 4 hours area under the curve (AUC) of nausea measured by Visual Analogue Scales.

    Measured: 4 hours

Secondary outcomes (4)
  1. Cmax of serum caffeine (in a subgroup)

    Measured: 4 hours

  2. Tmax of serum caffeine (in a subgroup)

    Measured: 4 hours

  3. t1/2 of serum caffeine (in a subgroup)

    Measured: 14 hours

  4. 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.

  1. First posted24 Jan 2007 (estimated)
  2. Study startJan 2007
  3. Primary completionFeb 2009
  4. Study completionFeb 2009

Resources

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)
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

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.

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