Treatment Fatigue in Multimorbidity: When Therapeutic Complexity Compromises Adherence and Clinical Outcomes

Abstract

Introduction: Multimorbidity is increasingly frequent in clinical practice and is associated with complex treatments, the simultaneous use of multiple medications, recurring consultations, diagnostic tests, and the need for therapeutic changes over time. Although these strategies are necessary to control chronic diseases, the sum of these demands can exceed the patient's capacity to properly maintain treatment, contributing to low adherence, abandonment of care, and a worsening quality of life. In this context, the concept of treatment fatigue allows us to understand the cumulative impact of the demands imposed by caring for multiple clinical conditions.

Objective: To discuss the concept of treatment fatigue in multimorbidity and its relationship with treatment complexity, adherence, quality of life, and clinical outcomes.

Methodology: This is an integrative literature review conducted across the PubMed, Scopus, and Virtual Health Library databases. The descriptors used were "Treatment Burden", "Treatment Fatigue", "Multimorbidity", "Polypharmacy", "Medication Adherence", "Chronic Disease", and "Patient-Centered Care", combined using the Boolean operators AND and OR. Studies published between 2020 and 2026, in English, Portuguese, or Spanish, that addressed the relationship between multimorbidity and the complexity of therapeutic demands were included. Case reports, letters to the editor, editorials, and studies without a direct relationship to the topic were excluded.

Results: The literature demonstrates that treatment burden results from various components, including the number of medications, frequency of doses, consultations, examinations, therapeutic adjustments, costs, and self-care demands. In patients with multimorbidity, the combination of these demands can produce physical and emotional overload, hinder the comprehension of recommendations, and compromise the continuity of care. Therapeutic complexity can also favor non-adherence behaviors, particularly when the perceived benefits of treatment are inferior to the effort required to carry it out. Strategies such as the simplification of medication regimens, prioritization of therapeutic goals, and shared decision-making can reduce this overload.

Conclusions: Treatment fatigue represents a relevant perspective for understanding the difficulties faced by patients with multimorbidity. Considering not only the number of diseases, but also the effort required to manage treatment, can foster more individualized and realistic clinical decisions. Incorporating this concept into internal medicine practice can help reduce excessively complex treatments and improve the continuity of care.