A compromise that is sometimes used is randomized, open treatment with utilization of masked raters, but care needs to be taken to maintain the masking. Treatment selection The choice of treatment and control(s) will, of course, be heavily influenced by the basic question that the RCT is intended to address. The choice of active control and the target dose(s)

of both the investigational medicine and the control agent are important. Estimates of therapeutic equivalence and comparative adverse effect profiles are affected by these choices. Inhibitors,research,lifescience,medical If a dose is too low, efficacy may be suboptimal, but if a dose is too high it might inflate the incidence of adverse effects. Titration schedules can also be important Inhibitors,research,lifescience,medical for some drugs as well as bioavailability

issues selleck chemicals related to food ingestion, or metabolic issues related to smoking, body weight, concomitant medications, etc. The side effect profiles of the experimental drug and comparator can also lead to functional unblinding and should be considered from that standpoint as well, or methods can be used to reduce the likelihood of such effects by using an ineffective low dose of the experimental drug as a pseudoplacebo, or separating the ratings of efficacy from those of tolerability, or using centralized raters who do not follow the same patient Inhibitors,research,lifescience,medical through a trial. An important and potentially difficult issue is the Inhibitors,research,lifescience,medical extent to which and what kind of “rescue” medication should be made available to those individuals who might otherwise drop out of the trial due

to lack of efficacy- and need for further treatment. This possibility can complicate the assessment of the therapeutic agent. However, in some settings it is difficult to conduct a controlled trial without such a provision. As will be discussed Inhibitors,research,lifescience,medical subsequently, the possibility of treating all patients initially with active agents, identifying those with a clear early response and then enrolling only the latter subjects in a double -blind, placebo controlled discontinuation study could be a powerful strategy to detect a true drug effect unless while exposing a minimal number of patients to placebo. Comedications The permission, timing, and dosing of comedications also requires consideration. Comedications are useful to limit adverse effect burden and dropouts, but can obscure true treatment effects. Moreover, differential washout of comedications in treatment groups prior to randomization can create confounds, whereas overly limited use of comedications might limit the feasibility of the trial and not match clinical reality. Placebo controls Recent discussion regarding placebo controlled clinical trials in schizophrenia has largely focused on ethical issues.