■ Only take drug if necessary or use drug as intended ■ 5R's (right patient, right drug, right time, right dose, and right route) refer to a carefully considered pattern of behavior on the part of the prescriber and the consumer. limit the use of medicines to situations where there are clear valid indications for them “patients receive medicines appropriate for their clinical needs, in doses that meet their individual requirements, for an adequate period of time, and at the lowest possible cost to them and their communities.” - WHO