Medical Information on the Internet
Module 4: Clinical Trials
- Clinical trial
- A research study conducted to answer specific questions, usually on the safety and effectiveness of a particular treatment.
- In Phase I trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
- In Phase II trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
- In Phase III trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- In Phase IV trials, post-marketing studies delineate additional information including the drug's risks, benefits, and optimal use.
- Source: Resources page at Clinicaltrials.gov Website (new window).