This proposal aims to increase our fundamental understanding of drug-related problems (DRPs), with the primary goal of significantly enhancing rational drug use through pharmacist-led interventions in primary care. We will focus our efforts on three key objectives:

1. Investigating the impact of pharmacist-led interventions on the occurrence of DRPs such as medication nonadherence in vulnerable patient populations (e.g. community-dwelling polypharmacy-patients).
2. Investigating issues with medication adherence in a currently understudied, vulnerable patient population, i.e. children. We aim to deepen our understanding of the barriers children face in adhering to their prescribed medication regimens. This knowledge will inform the development of strategies to improve pediatric medication adherence.
3. Enhancing communication of medication side effects. We endeavor to develop improved communication strategies for pharmacists to inform patients about the potential side effects of their medications.