NCT01501747

The Placebo Effect May Involve Modulating Drug Bioavailability

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 162 (actual)
• Sponsor: King Faisal Specialist Hospital & Research Center · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

The total effect of a medication is the sum of its drug effect, placebo effect (meaning response of placebo), and their interaction. Current interpretation of clinical trials (the gold standard of evidence-based-medicine) assumes no interaction, and the mechanism(s) underlying such interaction have not been fully explored. One possibility is that the placebo effect may modulate drug bioavailability. Using caffeine as a model drug, we have recently shown that the placebo effect of caffeine ingestion prolongs caffeine half life. Due to the novelty of this finding and its important clinical practice and clinical research implications, it needs to be confirmed in another set of subjects and extended to additional drugs. The results of the study are expected to further our understanding of the mechanism of action of a widely used medical intervention, i.e., placebo. The results will be important for both clinical practice and clinical research.

Detailed description

The total effect of a medication is the sum of its drug effect, placebo effect (meaning response of placebo), and their interaction. Current interpretation of clinical trials (the gold standard of evidence-based-medicine) assumes no interaction, and the mechanism(s) underlying such interaction have not been fully explored. One possibility is that the placebo effect may modulate drug bioavailability. Using caffeine as a model drug, we have recently shown that the placebo effect of caffeine ingestion prolongs caffeine half life. Due to the novelty of this finding and its important clinical practice and clinical research implications, it needs to be confirmed in another set of subjects and extended to additional drugs. DESIGN: Balanced cross-over, single-dose, two-period, two-group deign comparing caffeine, paracetamol, cephalexin, and ibuprofen described as such (overt) to the same medication described as placebo (covert). METHODS: 32, 50, 50, and 30 healthy adult volunteers will be enrolled in the caffeine (300 mg), paracetamol (500 mg), cephalexin (500 mg), and ibuprofen (400 mg) cross-over studies, respectively. Volunteers will be partially deceived to the intervention assignment (i.e., in the covert arm). Serum levels of each drug will be blindly determined by locally validated HPLC assays. Plasma half life (primary outcome) as well as Cmax, Tmax, and AUC (secondary outcomes) of each drug will be determined and analyzed by ANOVA.

Conditions

• Placebo Effect
• Drug Half Life
• Pharmacokinetics

Interventions

Type	Name	Description
DRUG	Caffeine, paracetamol, cephalexin, or ibuprofen	The study has 4 sub-parts (one for each of 4 drugs), each sub-part has a crossover design. In this arm, the volunteer will be given one oral dose of 300 mg caffeine, 500 mg paracetamol, 500 mg cephalexin, or 400 mg ibuprofen and will be told that they are receiving the active drug.
DRUG	Placebo (caffeine, paracetamol, cephalexin, or ibuprofen)	The study has 4 sub-parts (one for each of 4 drugs), each sub-part has a crossover design. In this arm, the volunteer will be given one oral dose of 300 mg caffeine, 500 mg paracetamol, 500 mg cephalexin, or 400 mg ibuprofen and will be told that they are receiving a placebo.

Timeline

• Start date: 2012-02-01
• Primary completion: 2013-02-01
• Completion: 2013-02-01
• First posted: 2011-12-29
• Last updated: 2013-04-09

Locations

1 site across 1 country: Saudi Arabia