Clinical Pharmacological Research

Clinical trials are research studies done in people that aim to evaluate a medical, surgical, or behavioral intervention. They are the main way researchers find out if a new treatment, such as a new drug, diet, or medical device (for example, a pacemaker) is safe and effective in people. A clinical trial is often used to find out if a new treatment is more effective and / or has less harmful side effects than standard treatment.

Why participate in a
clinical trial?

There are many reasons why people choose to enter a clinical trial. Some do it because the treatments they have used have not worked. Others participate because there is no treatment for their health problem. Being part of a clinical study allows participants to access new treatments before they are available. Some studies are designed to include healthy people who want to prevent diseases that, for example, affect relatives or close people.

What are the 4 phases of a
clinical study?

CLINICAL STUDIES go through four phases to evaluate a treatment, find the appropriate dose, and check for side effects. If after the first three phases researchers find a drug or other intervention that is safe and effective, the FDA authorizes it for clinical use and continues to monitor its side effects. The description of each drug emerges from the phases of the clinical studies. The FDA generally requests phases I, II, and III to determine approval for use.


The safety and adverse effects of an experimental treatment are evaluated in a small group of healthy patients (20 to 80) to find the correct dose.


It is done in more people (100 to 300). While the objective of Phase I is to evaluate safety, Phase II attempts to evaluate effectiveness. The purpose of this phase is to obtain preliminary information on whether the drug works in patients with a certain disease or condition. In addition, these studies continue to study safety, including medium and long-term adverse effects. This phase can last several years.


In this phase, more information about safety and effectiveness is collected by studying different types of population and doses, using the drug in combination with another. The number of participants generally ranges from several hundred to 3,000. If the FDA finds that the study results are positive, it will approve the investigational drug or device.


It is done for both drugs and devices after they have received approval for use from the FDA. The effectiveness and safety of the device or drug are monitored in large and diverse populations. Sometimes the adverse effects of any of them are not clear enough until they have been evaluated in more patients for a longer period of time.