Clinical Trial Basics
The clinical trials with which most people are familiar, called Phase III trials, are designed to compare the best available treatment for a condition or disease with a newer treatment option that may be more effective. Sometimes the newer option will involve brand new medications. Other times, the clinical trial simply may test existing medications in different combinations or different doses. These trials evaluate the benefits and risks of a treatment and gather information needed for labeling purposes.
In addition to this type of trial, there are phase I, II, and IV clinical trials.
In phase I trials, researchers study how a medication is metabolized (processed) in the body, what side effects are associated with increasing doses, any evidence that the medication is effective, and possible problems with toxicity. Phase I clinical trials may include healthy individuals.
In phase II trials, researchers look more closely at a treatment's effectiveness. These studies also further identify common short-term side effects and potential risks of a medication.
Phase IV clinical trials are post-marketing studies. Once a medication is approved for use in the population, the drug manufacturer will collect additional information, including the drug's risks, benefits, long-term side effects, and optimal use.
Sources Clinical Trials.gov. Accessed: March 17, 2009. http://www.clinicaltrials.gov/
