Hemolytic anemia in patients receiving sulfasalazine.

Hemolytic anemia is a well-recognized complication of sulfasalazine treatment. 17 of 40 (43%) patients with inflammatory bowel disease receiving sulfasalazine had evidence of hemolysis as detected by starch gel electrophoresis. Only 47% (8) of patients with hemolysis had Heinz body formation. The hemoglobin was significantly reduced in patients with hemolysis and 53% had a reticulocyte count of greater than 5%. A significant correlation was noted between hemolysis and serum sulfapyridine level, but no correlation was seen with serum sulfasalazine level. There was no significant difference in disease extent or activity in patients with hemolysis compared to those without hemolysis. Hemolysis is not a rare side-effect of sulfasalazine therapy. Heinz body formation is not invariably found in sulfasalazine-induced hemolysis.