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Study Title and Description

Stimulant and relaxant drugs combined with stimulant and relaxant information: a study of active placebo.



Key Questions Addressed
1 For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on cardiovascular outcomes?
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Primary Publication Information
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TitleData
Title Stimulant and relaxant drugs combined with stimulant and relaxant information: a study of active placebo.
Author MA Flaten,T Simonsen,K Zahlsen,T Aamo,G Sager,H Olsen,
Country
Year 2004
Numbers

Secondary Publication Information
There are currently no secondary publications defined for this study.


Extraction Form: Cardiovascular Design
Design Details
Question... Follow Up Answer Follow-up Answer
What outcome is being evaluated in this paper? Cardiovascular
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What is the objective of the study (as reported by the authors)? The active placebo hypothesis was tested in an experiment where information about the effect of a drug was combined with administration of an active drug or placebo.
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Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods) Subjects Ninety-four drug-free subjects (65 women, 29 men, mean age 23.4 years, range 19–40 years) without previous or present illness or injuries as assessed by a medical examination, and with clinical chemistry parameters revealing normal liver and renal function, participated in the experiment. The subjects were students at the University of Tromsø, Tromsø College, or employees at the University Hospital of North Norway. Blood samples could not be drawn from three subjects and epinephrine data and drug concentration data are missing for those subjects. Chemicals Carisoprodol was from Dumex, and caffeine and lactose were from Norsk Medisinaldepot (Oslo, Norway). The capsules were hard gelatin size 1 capsules from Davcaps (Hertfordshire, UK). The capsules, which contained either 87.5 mg carisoprodol, 50 mg caffeine, or 87.5 mg lactose, were packed by the pharmacy at the University Hospital of North Norway. Apparatus and Stimuli Each subject received one of three types of information about the drug she was administered, depending on group (Relaxant, Stimulant, Placebo). All administration of drugs and lactose was double-blind, and was performed by uniformed nurses. All substances were administered as eight white capsules that were swallowed with a glass of water. For one-third of the subjects the eight capsules contained a total of 700 mg carisoprodol (i.e. groups Relaxant/CSP, Stimulant/CSP and Placebo/CSP), for one-third of the subjects the eight capsules contained a total of 400 mg caffeine (i.e. groups Relaxant/CAF, Stimulant/CAF and Placebo/CAF), and for one-third of the subjects the eight capsules contained a total of 700 mg lactose (i.e. groups Relaxant/LAC, Stimulant/LAC and Placebo/LAC). Procedure The subjects were allocated to the nine groups according to a semi-random procedure. The subjects met in the laboratory at about 8 a.m. The subjects had been asked to abstain from breakfast and not drink any beverage in the morning prior to the experiment. After arrival in the laboratory, the subjects received one or two slices of bread with orange marmalade and a glass of apple juice. The subject was seated in a comfortable armchair. About 45 min after arrival in the laboratory, blood pressure was recorded 3 times with a 2-min break between each recording. About 50 min after arrival in the laboratory the first blood sample was taken. These data constitute the pre-tests. About 60 min after arrival in the laboratory, the subjects received information about the drug, and the capsules were administered. Blood pressure and heart rate monitored 25, 55, 70, 190, and 250 min after capsules were administered. Blood sample collected 40, 85, 115, 160, 220, and 280 minutes after capsules were administered. A light meal was served at 120 min. Response Scoring and Data Treatment Plasma catecolamine samples (1–2 ml) were spiked with known concentrations of the internal standard (dihydroxy-benzylamine) and added 1 ml of 2 M Tris–EDTA buffer (pH 8.7). The catecholamines were adsorbed onto alumina (10 mg). After aspiration of plasma/buffer, the alumina was washed 3 times with bi-distilled water (1 ml). The catecholamines were eluted from the alumina with a mixture (100 μl) comprising acetic acid (175 mM), sodium disulfide (9 mM) and EDTA (0.7 mM). The alumina was separated from the aqueous phase by filtration (Microfilter cartridges for low-volume sample clean-up; Bioanalytical Systems, Inc., West Lafayette, Ind., USA). Catecholamine levels were determined by a HPLC method. Design and Statistics The design was a 3 Drug (carisoprodol, caffeine, placebo) x Information (relaxant, stimulant, placebo) x Test mixed design, with the two first factors treated as between-subjects factors and the third factor treated as a repeated measures factor. The data were analysed by analysis of variance and by the Pearson product-moment correlation. An alpha-value of 0.05 was used. When several tests were performed, the alpha-value was Bonferroni corrected. Follow-up tests were performed by the Newman–Keuls statistic or the sign test.
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How many outcome-specific endpoints are evaluated? 3
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What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately) Blood pressure (SBP, DBP)
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List additional health endpoints (separately). 2 Heart rate
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List additional health endpoints (separately).3 Plasma catecholamines (epinephrine)
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List additional health endpoints (separately).4
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List additional health endpoints (separately).5
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List additional health endpoints (separately).6
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Clinical, physiological, other Physiological
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What is the study design? Controlled Trial
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Randomized or Non-Randomized? RCT
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What were the diagnostics or methods used to measure the outcome? Objective
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Optional: Name of Method or short description Method not specified
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Caffeine (general) Caffeine (general)
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Coffee, Chocolate, energy drink, gum, medicine/supplement, soda, tea, other?
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Measured or self reported? Measured
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Children, adolescents, adults, or pregnant included? Adults
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What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.) Subjects served as their own controls
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What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models.  Copy from methods) None
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What conflicts of interest were reported? No information provided
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Refid 15549277
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What were the sources of funding? The study was supported by The Council for Psychiatric Health (project number 97/1060) and the Norwegian Science Foundation (project numbers 122709/320 and 115012/320).
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Results & Comparisons

No Results found.