A case of adrenal insufficiency after initiation of targeted release budesonide formulation (Nefecon) in a Patient with IgA nephropathy

Abstract We describe a case of IgA nephropathy (IgAN) treated with targeted-release budesonide (Nefecon) that resulted in notable systemic adverse effects. The patient developed Cushingoid features, weight gain, hyperglycemia, and leukocytosis within 3 months of therapy. During dose tapering, he experienced symptomatic adrenal insufficiency confirmed by low morning cortisol, requiring hydrocortisone replacement. Despite Nefecon’s design for terminal ileum absorption and hence assumed minimal systemic exposure, this case demonstrates clinically significant adverse effects and adrenal suppression. These findings underscore the need for careful monitoring and patient education when initiating and tapering Nefecon in IgAN management.