Mesalazine induced focal segmental glomerulosclerosis in a patient with ulcerative colitis

Focal segmental glomerulosclerosis (FSGS) and other glomerulonephritis due to the use of 5-aminosalicylic acid derivatives have been reported in the literature. A 38-year-old male who had been using mesalazine for four years because of ulcerative colitis applied to doctor due to swelling in the lower extremities. The patient was diagnosed with nephrotic syndrome (NS). Renal biopsy was performed, and FSGS was diagnosed. Antiproteinuric treatments were initiated with steroid therapy. The patient has been followed with the normal renal function of the after treatment. 5-aminosalicylic acid derivatives affect renal functions at different levels and caused in NS.