Should You Take Part in a Clinical Research Trial?
After thoroughly investigating drugs or other treatments using laboratory animals, researchers design studies, called "clinical trials." The purpose of these trials is to test the treatments' safety and effectiveness in people. To receive approval from the United States Food and Drug Administration (FDA) for a new drug, manufacturers must prove that the agent works in humans and is not dangerous. They do this by submitting results from a series of clinical trials.
Many Phases of StudyClinical trials involve a multiphase process, which usually follows this pattern:The first phase typically lasts around 18 months. It tests the safety of using the drug in humans and only enrolls a small number of volunteers. Healthy people usually participate and can tell researchers if they experience side effects. Blood levels of the drug are often measured so that scientists can estimate a likely effective dosage.If new drugs are deemed safe, they move on to Phase II. This phase helps give an early indication of whether a drug will be effective. It is designed to establish what test conditions will be needed in Phase III to ultimately demonstrate a treatment's effectiveness. By using drugs in various combinations of dosages, researchers decide on what the best dose and timing of the treatment will be for the final phase of testing. Phase II typically involves a relatively small number of patients and lasts about two years. Phase II studies may or may not involve a “control” group of patients who receive only a non-active placebo.Drugs that pass Phase II move on to Phase III. In this phase, researchers compare the agent to the current standard of treatment or a placebo, an inactive ingredient. This phase lasts 1-4 years and will ultimately determine whether the treatment is effective. Depending on the disease studied, hundreds or even thousands of people may be enrolled.
Double-Blind StudiesIn a double-blind study, neither the participants who are enrolled nor their doctors are told which drug or treatment the participant is receiving. Double-blind studies typically occur in Phase II and III trials.
Who Is Eligible for Clinical Trials?Eligibility criteria for clinical trials are stringent so that scientists can measure results with fewer complicating factors, such as previous treatments or medications taken for unrelated conditions. But finding enough people who meet those requirements takes time, often several years.
More from Beliefnet