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Measuring Placebo Effect by Elimination and Investigating Mechanism of Action

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ClinicalTrials.gov Identifier: NCT00426010
Recruitment Status : Completed
First Posted : January 24, 2007
Last Update Posted : December 13, 2011
Sponsor:
Collaborator:
Information provided by:

Study Description
Brief 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.

Condition or disease Intervention/treatment
Placebo Effect Placebo Mechanisms of Action Drug: caffeine/placebo

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

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 180 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Measuring Placebo Effect by Elimination and Investigating Its Mechanism of Action
Study Start Date : January 2007
Primary Completion Date : February 2009
Study Completion Date : February 2009

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Caffeine
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Active Comparator: 1
overt then covert caffeine
Drug: caffeine/placebo
caffeine or placebo, either overt or covert
Active Comparator: 2
covert then overt caffeine
Drug: caffeine/placebo
caffeine or placebo, either overt or covert
Active Comparator: 3
overt then covert placebo
Drug: caffeine/placebo
caffeine or placebo, either overt or covert
Active Comparator: 4
covert then overt placebo
Drug: caffeine/placebo
caffeine or placebo, either overt or covert


Outcome Measures

Primary Outcome Measures :
  1. 4 hours area under the curve (AUC) of peripheral systolic blood pressure [ Time Frame: 4 hours ]
  2. 4 hours area under the curve (AUC) of energy level measured by Visual Analogue Scales. [ Time Frame: 4 hours ]
  3. 4 hours area under the curve (AUC) of alertness level measured by Visual Analogue Scales. [ Time Frame: 4 hours ]
  4. 4 hours area under the curve (AUC) of nausea measured by Visual Analogue Scales. [ Time Frame: 4 hours ]

Secondary Outcome Measures :
  1. Cmax of serum caffeine (in a subgroup) [ Time Frame: 4 hours ]
  2. Tmax of serum caffeine (in a subgroup) [ Time Frame: 4 hours ]
  3. t1/2 of serum caffeine (in a subgroup) [ Time Frame: 14 hours ]
  4. AUC of serum caffeine (in a subgroup) [ Time Frame: 14 hours ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Males and nonpregnant females 18 and 40 years of age with at least high school education.

Exclusion criteria:

  • 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,
  • 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
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00426010


Locations
Saudi Arabia
Center for Clinical Studies & Empirical Ethics, KFSH & RC
Riyadh, Saudi Arabia, 11211
Sponsors and Collaborators
King Faisal Specialist Hospital & Research Center
King AbdulAziz City for Science and Technology
Investigators
Principal Investigator: Muhammad M Hammami, MD, PhD KFSH & RC, Riyadh
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Muhammad Hammami, King faisal specialist hospital & research center
ClinicalTrials.gov Identifier: NCT00426010     History of Changes
Other Study ID Numbers: RAC# 2051072
KACST:ARP-26-45
First Posted: January 24, 2007    Key Record Dates
Last Update Posted: December 13, 2011
Last Verified: December 2011

Keywords provided by King Faisal Specialist Hospital & Research Center:
Placebo effect
Caffeine
Systolic BP
VAS

Additional relevant MeSH terms:
Caffeine
Central Nervous System Stimulants
Physiological Effects of Drugs
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Purinergic P1 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents