Estimation and Characterization of Adverse Drug Reactions Induced by Immunomodulators in Connective Tissue Disorders: A Hospital-based Cross-sectional Study

Background: Immunomodulators are foundational in managing connective tissue disorders connective tissue disorders (CTDs) but can produce significant adverse drug reactions (ADRs) that might affect adherence and outcomes. Methodology: A cross-sectional observational study was conducted over 6 months at AIIMS Nagpur among adults with CTDs receiving immunomodulators for >1 month. Standard causality (World Health Organization/Uppsala Monitoring Center [WHO-UMC], Naranjo), severity (Hartwig–Siegel), and preventability (Schumock–Thornton) scales were applied and associations were assessed using the Chi-square test. Results: Among 105 patients (mean age 42.68 ± 15.55 years; 76.2% female), 19 ADRs were identified. Drugs most implicated included prednisolone, methotrexate, and hydroxychloroquine, with typical events such as central serous retinopathy, hypertension, oral ulcers, and rashes. Causality was mostly probable by WHO-UMC (71.4%) and Naranjo (57.9%); severity was mild-to-moderate (89.5%); preventability was mostly probable (84.2%); no life-threatening outcomes occurred, and 73.7% recovered fully by last follow-up. No significant associations were found between ADR occurrence and sex, age group, or comorbidity status (all P > 0.05). Conclusion: In CTDs, immunomodulator-related ADRs were predominantly probable, mild-to-moderate, and largely preventable. Routine monitoring and patient counseling can reduce avoidable harm.