Contemporary medicine is based on the principle that people are treated only in ways that are proven to be effective and safe. The safety and effectiveness of medicines can be assessed in many ways, but definitive conclusions can be made only based on human research. In Baltic countries (Estonia, Latvia and Lithuania), the number of pharmaceutical studies has increased year by year. Thereby the opportunity of being proposed to participate in a pharmaceutical study while going to a doctor is also increasing. The participation is always voluntary.

Clinical study is regulated and controlled usage of the new drugs in humans to gather data about clinical effects, adverse reactions, absorption, distribution, biotransformation, excretion, efficacy and safety.

Humans studies are always preceded by a thorough non-clinical (pharmacology, toxicology, pharmacokinetics and metabolism-related) studies and studies in laboratory animals, which explain as closely as possible the qualities of examined medicine and the prognosed impact to humans. If the efficacy of a new medicine to humans is found to be too low and / or too dangerous, the clinical study will not be started.

4 different phases are distinguished in pharmaceutical studies in humans and these phases are required in the process of developing new medicines. The phases follow each other chronologically.

The purpose of phase I studies is to adjust the data that is clarified in non-clinical studies (adverse drug reactions and used dose). The study drug is given to a very small group of people – usually to healthy volunteers or more rarely to the patients suffering from respective diseases, the study takes place in hospital.

The purpose of phase II studies is to evaluate the efficacy and safety of a study drug on a relatively small number of patients with the respective disease. The patients take medicine according to doctor’s prescription in usual way, in accordance with their state of health – in home or in hospital.

In the phase III studies the new drugs are compared to existing therapies on a large number of patients.

The studies of phase IV take place after the medication is allowed to the market, but the efficacy and safety related data is continuously collected. The people, who are taking medications, are still under heightened attention of doctors.

There are different rules and number of laws that handle the various aspects of studies. These are necessary to prove that the conduction of clinical studies is ethically acceptable; the rights of participants are protected and the results of the studies are reliable.

The procedures about clinical studies are available on websites of Regulatory Authorities of concerned country.