Measuring Placebo Effect by Elimination and Investigating Mechanism of Action

This study has been completed.
Sponsor:
Collaborator:
King AbdulAziz City for Science and Technology
Information provided by:
King Faisal Specialist Hospital & Research Center
ClinicalTrials.gov Identifier:
NCT00426010
First received: January 23, 2007
Last updated: December 11, 2011
Last verified: December 2011
  Purpose

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 Intervention
Placebo Effect
Placebo Mechanisms of Action
Drug: caffeine/placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Measuring Placebo Effect by Elimination and Investigating Its Mechanism of Action

Resource links provided by NLM:


Further study details as provided by King Faisal Specialist Hospital & Research Center:

Primary Outcome Measures:
  • 4 hours area under the curve (AUC) of peripheral systolic blood pressure [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
  • 4 hours area under the curve (AUC) of energy level measured by Visual Analogue Scales. [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
  • 4 hours area under the curve (AUC) of alertness level measured by Visual Analogue Scales. [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
  • 4 hours area under the curve (AUC) of nausea measured by Visual Analogue Scales. [ Time Frame: 4 hours ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Cmax of serum caffeine (in a subgroup) [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
  • Tmax of serum caffeine (in a subgroup) [ Time Frame: 4 hours ] [ Designated as safety issue: No ]
  • t1/2 of serum caffeine (in a subgroup) [ Time Frame: 14 hours ] [ Designated as safety issue: No ]
  • AUC of serum caffeine (in a subgroup) [ Time Frame: 14 hours ] [ Designated as safety issue: No ]

Estimated Enrollment: 180
Study Start Date: January 2007
Study Completion Date: February 2009
Primary Completion Date: February 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.

  Eligibility

Ages Eligible for Study:   18 Years to 40 Years
Genders Eligible for Study:   Both
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
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: 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

No publications provided by King Faisal Specialist Hospital & Research Center

Additional 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
Study First Received: January 23, 2007
Last Updated: December 11, 2011
Health Authority: Saudi Arabia: Research Advisory Council, KFSH & RC
Saudi Arabia: King Abdulaziz City for Science & Technology (KACST)

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

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

ClinicalTrials.gov processed this record on October 22, 2014