Medication-Related Problems in Patients with Multiple Chronic Diseases: Prevalence, Risk Factors, and Clinical Consequences

Abstract

People with multiple chronic diseases often have to take multiple medications to control their disease and avoid complications. Medication-related problems (MRPs), such as adverse drug reactions, ineffective treatment, inappropriate drug or dose selection, drug-drug and drug-disease interactions, lack of treatment at all, duplication of therapy, nonadherence, and lack of monitoring, can occur with high frequency in therapeutic complexity. This narrative review aims to summarize evidence regarding the prevalence, determinants, and clinical consequences of MRPs in people with multimorbidity, specifically focusing on the effects of polypharmacy, older age, renal impairment, fragmented prescribing and transition of care, and burden of treatment. Prevalence rates vary significantly in the literature because populations, care settings, detection methods, and classification systems differ. However, MRPs are always prevalent in the multimorbid population: high proportions of patients are found in hospital studies, and drug-related hospitalizations can constitute a significant proportion of admissions in selected high-risk patient groups. The risk increases as the number of medicines increases, as more high-risk medicines are taken, and with kidney and

liver impairment, frailty, cognitive and functional limitations, multiple prescribers, complex medicine regimens, and poor reconciliation and monitoring. The consequences are not limited to adverse drug reactions; they also include poor disease control, falls, delirium, functional decline, emergency visits, hospitalization, readmission, longer hospital stays, lower quality of life, increased costs, and the avoidance of death. Medication review, medication reconciliation, patient-centered deprescribing, use of validated tools for medication checklists, renal dose adjustment, adherence support and involvement of pharmacists in multidisciplinary care are key strategies to prevent. The evidence is consistent with the call to move away from disease-by-disease prescription to medicines optimization for people with multimorbidity in a coordinated and goal-oriented manner.