[Drug evaluation in neuroanesthesia and resuscitation]

The evaluation of a drug used in neuroanesthesia is based upon controlled trials. The main principles of such trials are not different from trials of other drugs but some characteristics should be emphasized. The first phase of the development of a drug is an evaluation in healthy volunteers of its tolerance and kinetics, which must combine rapid and short action without residual effect. The second phase is a study of the tolerance and kinetics but also of its efficacy because only patients are involved. Action upon cerebral circulation is of great importance. During the third phase, trials have to prove that the new drug has "something more" than the drug usually prescribed for the same indication to obtain approval for marketing. The next phase is the best period for the evaluation of safety by recording the adverse effects observed when many patients are exposed to the new drug. The french system of post marketing surveillance is based upon spontaneous reports of adverse effects by prescribers To be correctly performed a trial needs the collaboration of a neuroanesthetist, a pharmacologist and a statistician. The trial needs to be controlled which means a comparison of two groups of patients, one with the drug and the other one without the drug. The treatment has to be randomized and blind to be sure that any difference between the two groups is in fact due to the drug. The clinician has to define the evaluation criteria and the tool of measurement to calculate the number of patients needed for the purpose of the trial.