title: Optimization of placebos for double-blind clinical trials. Experience with a phytopharmaceutical.
abstract: The maintenance of double-blind conditions in placebo-controlled trials depends on the quality of the placebo preparation. The placebo should match the active substance-containing preparation as closely as possible, but it must not contain any substances that might themselves be pharmacologically active. Active substances characterized by a particular colour, taste, smell or other easily perceptible properties constitute a challenge to researchers. The way of developing a placebo that matches a phytopharmaceutical to a satisfactory extent is described and discussed.
authors.affiliation: Department of Epidemiology, University of Maastricht, The Netherlands.
authors.forename: P G
authors.initials: PG
authors.lastname: Knipschild
authors.forename: R
authors.initials: R
authors.lastname: Hoerr
authors.forename: R
authors.initials: R
authors.lastname: Oschmann
authors.forename: E
authors.initials: E
authors.lastname: van Rossum
authors.forename: M C
authors.initials: MC
authors.lastname: van Dongen
mesh_terms: D000368:Aged; D002491:Central Nervous System Agents / Q000627:therapeutic use*; D002985:Clinical Protocols / Q000592:standards*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005419:Flavonoids / Q000627:therapeutic use*; D020441:Ginkgo biloba; D006801:Humans; D008569:Memory Disorders / Q000188:drug therapy* / Q000209:etiology; D010919:Placebos; D010936:Plant Extracts / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards; D000096983:Ginkgo Extract
chemical_list: D002491:Central Nervous System Agents; D005419:Flavonoids; D010919:Placebos; D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract