Iatrogenic injury from adverse drug events (ADEs) is a common and often preventable problem in modern medical practice. Attention to this problem has focused on the inpatient hospital setting and healthcare professionals. However, most medication is prescribed and used outside of hospitals and is managed by patients or lay caregivers in homes or workplaces. To address the public health problem of outpatient drug safety, interventions to prevent adverse events must recognize the central role of the patient in medication management and environmental factors specific to the outpatient setting. Lessons and techniques from the field of injury prevention should guide the development and implementation of safety interventions. First, Haddon's phase-factor matrix can be used to help conceptualize outpatient drug safety interventions. Second, interventions to improve outpatient drug safety should be patient-centered and extend beyond patient education to include engineering innovations and enforcement strategies. Third, the sustainability of active versus passive interventions should be considered when choosing safety interventions.