Instability of Hematin Used in the Treatment of Acute Hepatic Porphyria

The acute hepatic porphyrias are diseases in which the production of heme is deficient because of inherited abnormalities in specific enzymes of the heme synthetic pathway.1 The goal of therapy for these diseases is replenishment of cellular heme. This has been attempted clinically with intravenous administration of heme.2 3 4 Because of its poor solubility at neutral pH, heme is prepared as hematin in a bicarbonate solution at a pH of 8. Initial reports indicated that hematin was remarkably effective in severe acute porphyric attacks.2 , 3 However, the results were not uniform, and a more recent study suggested that hematin was frequently ineffective. . . .