Polypharmacy and potential drug–drug interactions in patients with rheumatoid arthritis

Abstract

Background: Rheumatoid arthritis (RA) is a systemic autoimmune disease with protean manifestations. It is characterized by symmetric polyarticular inflammation, which can lead to progressive joint damage. As a result, RA is associated with substantial functional disability, morbidity, and accelerated mortality, which pose an enormous and growing societal burden. Polypharmacy is a major public health concern, which is growing worldwide. Polypharmacy is associated with adverse outcomes including mortality, falls, adverse drug reactions, increased length of stay in hospital and readmission to hospital soon after discharge. Objectives: The aim of this study was to quantify polypharmacy in a group of patients with RA, its relationship with patients’ characteristics and to assess the risk of potential undesirable interactions between medications used for managing RA and those used for chronic and non-chronic diseases. Materials and Methods: A cross-sectional study was conducted at Baghdad Teaching Hospital, Rheumatology Unit during the period from December 2019 to December 2020. A total of 188 adult patients, previously diagnosed with RA according to the 2010 American College of Rheumatology/ European League against Rheumatism rheumatoid arthritis classification criteria, were included in the study. Data were collected using a pre-constructed data collection sheet. Questionnaires included demographic and clinical data of the patients. In this study, polypharmacy was defined as the association of five or more medications, regardless of the duration. Drug interactions were identified by use of the Medscape’s drug interaction checker® database. Results: Among 188 RA patients in this study, polypharmacy was found in 71.8% of the patients and there were 331 potential drug–drug interactions (1.77 ± 2.52 DDIs/patient). Most of the potential drug–drug interactions were related to the use of methotrexate, with nonsteroidal anti-inflammatory drugs being the major representative of these drug–drug interactions with methotrexate. Conclusion: High prevalence of polypharmacy was found in RA patients. Positive correlation between polypharmacy and patient’s age, disease activity and the presence of other comorbid conditions. Polypharmacy was associated with increased incidence of potential drug–drug interactions in RA patients. Methotrexate was involved in most drug–drug interactions.

Keywords

• drug–drug interactions and methotrexate
• polypharmacy
• rheumatoid arthritisdrug–drug