The population in western countries is aging and elderly people are more likely to suffer diseases and receive treatments. Adverse reactions to drugs are more severe and frequent in the elderly patients, who are also less likely to report them. The present paper analyses the age induced changes in drug pharmacokinetics. For the purpose of improving the quality of clinical trials in geriatric patients and to set a network of clinical research centres, this paper proposes a series of 9 milestones. They are named geriatric core data and should be collected in each trial.