STUDIES IN PORPHYRIA III, HEME, AND TIN MESOPORPHYRIN IN ACUTE PORPHYRIAS

急性卟啉症是一种遗传性代谢紊乱，会导致危及生命的神经症状，可以通过静脉注射血红素进行治疗。其目的是研究锡中卟啉(一种血红素降解的抑制剂)，以加强血红素治疗在这些疾病中的效果。其具体目的是：1)确定用于降低稳定的急性间歇性卟啉症患者的卟啉前体水平的锡、间卟啉和血红素的最佳剂量组合；2)与血红素一起使用时，锡中卟啉用于预防门脉病急性发作所需的安全性和有效性；3)锡中卟啉在减少输注血红素的频率方面的安全性和有效性。如果血红素Aregate的供应有限，可以替代血红素白蛋白。锡中卟啉很有可能被批准用于治疗新生儿黄疸，也将可用于治疗门静脉症。因此，重要的是要知道，正如初步报告所建议的那样，它是否安全有效，以及最佳剂量。这些研究将确定锡中卟啉是否安全有效，从而解决美国急性卟啉症患者的一个重要治疗选择。

Acute porphyrias are inherited metabolic disorders that cause life-threatening neurological symptoms, and are treated with intravenous heme. The objective is to study tin mesoporphyrin (an inhibitor of heme degradation) for enhancing the effects of heme therapy in these disorders. The specific aims are to determine 1)the optimal dose combinations of tin mesoporphyrin and heme for reducing porphyrin precursor levels in stable patients with acute intermittent porphyria; 2)safety and efficacy of tin mesoporphyrin when given with heme in acture attacks of porphyria 3)safety and efficacy of tin mesoporphyrin for decreasing the frequency heme infusions needed to prevent attacks of porphyria. Heme albumin may be substituted if the supply of heme areginate is limited. Tin mesoporphyrin is likely to be approved for treatment of neonatal jaundice, and will become available for use in porphyria as well. Therefore it is important to know if, as suggested by preliminary reports, it is safe an effective in porphyria and the optimal dosage. The studies will determine whether tin mesoporphyrin is safe and effective and thereby addresses an important management option for patients with acute porphyrias in the U.S.