Large scale collection of PK–PD observations should be pursuedandencouragedforbothnovelandestablished criticaldrugs.Pharmaceuticalcompaniesshouldbepressurizedtoreleaseandpublishtheirdataintimelyfashion and clinical laboratories in the public health service should complement this effort through multicentre research collaborations. Children and old people, often neglected during drug development, deserve such observational PK–PD studies.