<prompt> renal papillary necrosis is caused by ?alcoholcocaineheroinmorphine  <response>: Etiology Pyelonephritis Obstruction of the urinary tract Sickle cell hemoglobinopathies, including sickle cell trait Tuberculosis Cinhosis of the liver, chronic alcoholism Analgesic abuse Renal transplant rejection, Radiation, Renal vein thrombosis Diabetes mellitus Systemic vasculitis Renal papillary necrosis Renal papillary necrosis RPN is characterized by coagulative necrosis of the renal medullary pyramids and papillae Renal papillary necrosis generally affects individuals who are in the middle decades of life or older It is more common in women than in men 60 of the patients have DM, 30 Urinary tract obsruction, 15 have both. Renal papillary necrosis is primarily a bilateral process ref : harrisons 21st ed 