Understanding the Dual Challenge: Adverse Drug Reactions and Adherence in Rheumatoid Arthritis Treatment

The primary aim of this study was to investigate the real-world occurrence of various adverse drug reactions (ADRs) and assess medication adherence among patients using disease-modifying antirheumatic drugs (DMARDs). Additionally, the study sought to evaluate the degree of methotrexate intolerance among these patients.

This cross-sectional, observational study was conducted at a tertiary care hospital and involved 100 adult patients diagnosed with rheumatoid arthritis (RA) who were currently undergoing treatment with methotrexate. The study systematically recorded all adverse drug reactions reported by the patients as well as those identified through laboratory tests. Medication adherence was measured using the Compliance Questionnaire Rheumatology (CQR5) and both intentional and non-intentional non-adherence questionnaires. The methotrexate intolerance was assessed using the Methotrexate Intolerance Severity Score (MISS).

Out of the total 74 reported ADRs, gastrointestinal were the most common, accounting for 62 (76.53%) of cases, followed by hematological problems at 13 (16.07%), with other types of ADRs comprising the remaining. Despite the prevalence of gastrointestinal ADRs, the study found high levels of medication adherence among the patients. Additionally, the methotrexate intolerance was relatively low, which may be attributed to the use of folic acid supplementation by all participants.

Gastrointestinal adverse drug reactions were the most frequently observed side effects in this study. Despite these reactions, patients demonstrated a high level of adherence to methotrexate therapy. The factors contributing to this adherence- such as patient counseling, disease knowledge, or the duration of the disease- merit further investigation to understand their impact on treatment outcomes.