Navegando por Palavras-chave "placebo"

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    Effect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot study
    (Wiley-Blackwell, 2002-11-01) Andreatini, R.; Sartori, V. A.; Seabra, MLV; Leite, JR; Univ Fed Parana; Universidade Federal de São Paulo (UNIFESP)
    The aim of the present study was to carry out a controlled pilot study on the putative anxiolytic effect of valepotriates. Thirty-six outpatients with generalized anxiety disorder (DSM III-R), after a 2-week washout, were randomized to one of the following three treatments for 4 weeks (n = 12 per group): valepot-riates (mean daily dose: 81.3 mg), diazepam (mean daily dose: 6.5 mg), or placebo. A parallel, double-blind, flexible-dose, placebo-controlled design was employed. No significant difference was observed among the three groups at baseline or in the change from baseline on the Hamilton anxiety scale (HAM-A) or in the trait part of the state-trait anxiety inventory (STAI-trait). Moreover, the three groups presented a significant reduction in the total HAM-A scores. On the other hand, only the diazepam and valepotriates groups showed a significant reduction in the psychic factor of HAM-A. the diazepam group also presented a significant reduction of the STAI-trait. Although the principal analysis (HAM-A between group comparison) found negative results (probably due to the small sample size in each group), the preliminary data obtained in the present study suggest that the valepotriates may have a potential anxiolytic effect on the psychic symptoms of anxiety. However, since the number of subjects per group was very small, the present results must be viewed as preliminary. Thus, further studies addressing this issue are warranted. Copyright (C) 2002 John Wiley Sons, Ltd.
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    Is it ethical to use placebos in osteoporosis trials?
    (Elsevier B.V., 2006-07-01) Ragi-Eis, Sergio; Zerbini, Cristiano Augusto F.; Provenza, Jose R.; Griz, Luiz H. M.; Gregorio, Luiz H. de; Russo, Luis A. T.; Silva, Nilzio A.; Borges, Joao L. C.; Souza, Antonio C. A. de; Lazaretti-Castro, Marise [UNIFESP]; Lewiecki, E. Michael; Osteoporosis Diag & Res Ctr Espirito Santo; Hosp Heliopolis; Pontificia Univ Catolica Campinas; Universidade Federal de Pernambuco (UFPE); Clin Res Ctr; Universidade Federal de Goiás (UFG); Universidade de Brasília (UnB); PUC RS; Universidade Federal de São Paulo (UNIFESP); New Mexico Clin Res & Osteoporosis Ctr
    The use of placebo control groups (e.g., subjects using calcium and vitamin D) in osteoporosis trials with subjects at high risk for fracture has been systematically questioned by institutional review boards (IRBs). Regulatory agencies, on the other hand, continue to not only recommend but also require that placebo-controlled trials be presented for the registration of new drugs for osteoporosis treatment. the Declaration of Helsinki and its updates have upheld the principle that protection of research subjects' rights is of primary concern. Nevertheless, even the Declaration keeps clearly opening the possibility of using placebo-control designs if it is justified for compelling and scientifically sound methodological reasons. the use of intermediary endpoints or surrogates to establish the efficacy or safety of new medications in the management of osteoporosis is currently considered scientifically insufficient. This concept has led regulatory agencies, such as the Food and Drug Administration in the United States and the European Medicines Agency in the European Union, to require fragility fracture reduction as the primary endpoint in clinical trials for the registration of new drugs. Superiority or noninferiority trials are alternatives to placebo-controlled designs. However, factors such as sample size, cost, and statistical limitations render these models impractical for the registration of new medications for osteoporosis. We recommend collaboration among regulatory agencies, IRBs, scientists, and ethicists on the design of clinical trials for the registration of new medications for reduction of fracture risk. Delay in developing mutually acceptable models may impair scientific development in the field and possibly deprive patients of potentially beneficial treatments.