EVALUATION OF THE SAFETY PROFILE OF IMMUNOSUPPRESSANT DRUGS IN AUTOIMMUNE DISORDERS AND CAUSAL RELATIONSHIP OF REPORTED ADVERSE DRUG REACTIONS USING THE WHO–UMC SCALE

Autoimmune disorders are chronic conditions characterized by loss of immunological self-tolerance and inappropriate immune responses against self-tissues. Immunosuppressant and immunomodulatory medicines are central to the management of many autoimmune disorders because they reduce pathological immune activation, inflammation and progressive tissue injury. However, the same pharmacological actions may increase susceptibility to adverse drug reactions (ADRs), including infections, hematological abnormalities, nephrotoxicity, hepatotoxicity, gastrointestinal disturbances and metabolic complications. The present review discusses the pharmacological classes of immunosuppressants, their mechanisms of action, therapeutic applications, major safety concerns, monitoring requirements, pharmacovigilance principles and causality assessment of suspected ADRs using the World Health Organization–Uppsala Monitoring Centre (WHO–UMC) system. The review also examines the relevance of patient characteristics, concomitant medicines, treatment duration, laboratory findings, dechallenge/rechallenge information and alternative explanations in determining the likelihood of a causal relationship. WHO–UMC categories—Certain, Probable/Likely, Possible, Unlikely, Conditional/Unclassified and Unassessable/Unclassifiable—provide a clinically oriented framework for evaluating individual suspected ADR reports. Systematic pharmacovigilance and individualized monitoring are essential for balancing disease control with the risks of immunosuppressive therapy.