[Patient safety in clinical trials with drugs for human use]

A clinical trial is a planned study which aims to evaluate the effectiveness of health interventions. The first step of a clinical trial is to develop a hypothesis or a question which answer is desired. This question will be the main factor of the methodology of the trial, of the included subjects, of the type of trial, duration, etc. In turn, a number of essential elements among which we can mention staff (who must be qualified), adequate infrastructure, various contrasting sources of information, financial means are required to perform research enough and a working environment that will motivate the professionals for its realization. All this, in order to increase the quality services and respond to the most demanding requirements in the control and monitoring of existing drugs.