Situations in which placebo may be considered as a comparator, for example, might be when there is no commonly accepted therapy for the condition selleckchem and the investigational medicinal product is the first one that may modify the course of the disease process. It is useful when the commonly used therapy for the condition is of questionable efficacy or carries with it a high frequency of undesirable adverse reactions and the risks may be significantly greater than the benefits. Guidelines of the office for human research protection on placebo The Office for Human Research Protection (OHRP) published guidelines in 2008 for the use of placebo and methods to minimize the risk associated with it. The guidelines state, ??Placebos may be used in clinical trials where there is no known or available (i.
e., FDA-approved) alternative therapy that can be tolerated by subjects.?? The use of placebos in controlled clinical trials must be justified by a positive risk-benefit analysis, and the subjects must be fully informed of the risks involved in the assignment to the placebo group. Continued assignment of subjects to placebo is unethical, once there is good evidence to support the efficacy of the trial therapy. Some drug trials involve a period during which all participants receive only a placebo prior to the initiation of the study. This period is called a ??placebo washout??. The purposes of a washout period include: Terminating the effects of any drug the subject may have been taking before entering the clinical trial, so that the effects of the trial drug-and only the trial drug-may be observed.
Understanding whether the subjects co-operate with instructions to take drugs. Understanding which subjects are ??placebo responders??, in that they experience a high degree of placebo effect. In some protocols, the investigators plan to exclude those subjects they find either poorly compliant or highly responsive to the placebo. Methods that can be used to minimize risks associated with the use of placebo. Subjects with an increased risk of harm from non-response may be excluded. Increased monitoring for deterioration of subjects and the use of rescue medications may be included in the protocol. ??Early escape?? mechanisms and explicit withdrawal criteria may be built in so that subjects will not undergo prolonged placebo treatment if they are not doing well.
The size of the population placed on placebo may be kept smaller than the number in the active treatment arms. Placebo and active treatment may be compared in an ??add-on?? method, keeping the subjects on identical maintenance treatments and then adding on the active treatment to one arm and the placebo to the other. This design is especially applicable when the available treatment AV-951 is known to decrease mortality or morbidity. Shortened http://www.selleckchem.com/products/CAL-101.html treatment periods reduce the risks associated with delayed treatment.