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，可引起危及生命的神经系统症状，可用静脉注射血红素治疗。目的是研究中卟啉锡（一种血红素降解抑制剂），以增强这些疾病中血红素治疗的效果。具体目的是确定1)降低稳定型急性间歇性卟啉病患者卟啉前体水平的介卟啉锡和血红素的最佳剂量组合；2)甲卟啉锡联用血红素治疗卟啉症急性发作的安全性和有效性3)甲卟啉锡用于减少注射血红素预防卟啉症发作的频率的安全性和有效性。血红素白蛋白可以替代，如果供应血红素精氨酸是有限的。中卟啉锡很可能被批准用于治疗新生儿黄疸，也将可用于卟啉症。因此，重要的是要知道，如初步报告所建议的，它是安全的，有效的卟啉症和最佳剂量。这些研究将确定中卟啉锡是否安全有效，从而为美国急性卟啉症患者提供一个重要的治疗选择

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.