Aging is a global reality that is accompanied by an increase in polypharmacy. In this vital stage, caregivers emerge as relevant actors since their intervention impacts on the safety of the medication use process and on the quality of life of the patient they assist. As the knowledge about the treatments that caregivers supervise for the patient under their care conditions the health outcomes of the medications, the main objective of this study is to characterize the caregivers of patients who use opioid analgesics and to identify factors that increase the risk of the appearance of Medication Related Problems (DRP).The results reveal that the caregiver profile affects the health outcomes of this therapeutic group in both the prevalence and type of DRP. Of the 63 patients using opioid analgesics under pharmacotherapeutic follow-up during this study, 17 (27%) had caregivers. The caregiver in this study was predominantly female (61.1%).Considering DRP and kinship, a higher prevalence of DRP was observed when the caregivers were children or external personnel.Analyzing the pharmacotherapy of these caregivers, 4.8% have started antidepressant treatment, 3.2% hypnotic treatment after becoming caregivers of these patients. The Zarit Test reveals that 29.4% of the caregivers of these patients manifest overload.We conclude that Pharmaceutical Care should consider the opportunity and relevance of designing and implementing intervention and education protocols focused on caregivers.