Mark Ruscin, PharmD, FCCP, BCPS, Southern Illinois University Edwardsville School of Pharmacy; Sunny A Linnebur, PharmD, BCPS, BCGP, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Reviewed / Revised Jul 2021 | Modified Sep 2022 View Patient Education Reasons for Drug-Related Problems Prevention Topic Resources QT Interval Correction (EKG) Preventable Causes of Drug-Relate... Drug-Disease Interactions... Drug-related problems are common in older adults and include drug ineffectiveness, adverse drug effects, overdosage, underdosage, inappropriate treatment, inadequate monitoring, nonadherence, and drug interactions.