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William T Carpenter

Publications and source records attributed to William T Carpenter.

8 recordsLinked to original sources
PubMed2003

The Declaration of Helsinki and clinical trials: a focus on placebo-controlled trials in schizophrenia.

OBJECTIVE: The authors' goal was to consider ethical approaches to placebo-controlled clinical trials in the light of the evolving Declaration of Helsinki, with special attention to applications to research on schizophrenia. METHOD: They review the Helsinki position on placebos, including the 2002 Clarification, exploring the potential negative effects of banning placebos in studies involving conditions for which at least partially effective treatments exist. The Clarification is examined as an approach to this issue that, in contrast to earlier formulations, better acknowledges the complexity of clinical research and the need for protocol-specific determinations. Placebo controls in schizophrenia studies are used to illustrate issues relevant to all clinical research on therapeutic interventions. RESULTS: The Helsinki Clarification provides a basis for operationalizing criteria for review of placebo use in clinical trials. Six criteria are proposed for judging the ethical acceptability of placebo controls, including the likelihood that the intervention being tested will have clinically significant advantages over existing treatments, the presence of compelling reasons for placebo use, subject selection that minimizes the possibility of serious adverse consequences, and a risk-versus-benefit analysis that favors the advantages from placebo use over the risks to subjects. CONCLUSIONS: The Helsinki Clarification constitutes an important advance in international approaches to placebo use, requiring protocol-by-protocol judgments on complex issues of clinical research ethics. When operationalized, it provides review boards with a useful methodology for reaching determinations on the appropriateness of placebo controls in particular studies.

Controlled Clinical Trials as Topic↗
PubMed2003

The relationship of clozapine and haloperidol treatment response to prefrontal, hippocampal, and caudate brain volumes.

OBJECTIVE: The study was designed to assess the predictive relationship between brain structure volume and positive and negative symptom response to clozapine and haloperidol. METHOD: Partially responsive outpatients with schizophrenia who participated in a 10-week, parallel-group, double-blind comparison of clozapine and haloperidol and who had an available magnetic resonance imaging scan were included in the current study. Prefrontal gray and white matter, hippocampal, and caudate volumes were manually measured. The Scale for the Assessment of Negative Symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS) were used to assess symptom changes. The Simpson-Angus Rating Scale was used to assess extrapyramidal symptoms. RESULTS: Twenty-two patients randomly assigned to clozapine and 23 patients assigned to haloperidol met study entry criteria. There were significant interactions between treatment and right prefrontal gray matter volume for BPRS total score and SANS total score. There were no significant treatment-by-brain structure interactions for BPRS positive symptom items. Right prefrontal gray matter volume was also related to differential treatment effects for the BPRS subscales of anxiety/depression and hostility and the Simpson-Angus Rating Scale akathisia item. CONCLUSIONS: These results suggest that there is a differential interaction among clozapine and haloperidol, brain structure, and treatment response. Partially responsive patients with larger brain volumes may be more likely to experience the benefits of clozapine treatment, but they may be more vulnerable to side effects and experience a subsequent worsening of their symptoms when treated with haloperidol.

Adult↗
PubMed2002

From clinical trial to prescription.

There are many steps between drug discovery and prescribing for a patient. Each step has problems. In this issue of ARCHIVES, Klein and colleagues propose changes in clinical trials that would result in more meaningful information for the treating physician. Of particular importance is the gap between what a physician needs to know and what is produced in the clinical trials that leads to approval of a new drug by the US Food and Drug Administration (FDA). Their recommendations for improving clinical trials are cogent, but broad-based implementation depends on an organizational structure and political effectiveness not presently in place. Most important, as the authors note, is an effective work group representing industry, regulatory agencies, and academic and federal science, addressing clinical trials issues with public participation. While improved quality and relevance of data from clinical trials will strengthen the scientific foundation of pharmacotherapy, other problems impede the delivery of objective information to the treating physician. Most hotly debated is the role of money in the creation and dissemination of knowledge.

Clinical Trials as Topic↗