Clinical Trials Defined

[Guest guest]

Most clinical trials are designated as phase I, II, III, or IV, based

on the type of questions that study is seeking to answer.

In Phase I clinical 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 clinical 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 clinical 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 clinical trials, post marketing studies delineate

additional information including the drug's risks, benefits, and

optimal use.

These phases are defined by the Food and Drug Administration in the

Code of Federal Regulations. I suppose that it's much the same in

Great Britain and elsewhere.