Studies in Porphyria III: Heme and Tin Mesoporphyrin in Acute Porphyrias

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- * Documented acute intermittent porphyria in remission for at least 1 month * Increased excretion of porphyrin precursors * Absence of neurovisceral symptoms due to porphyria for at least 1 month --Prior/Concurrent Therapy-- * At least 1 month since prior heme preparation therapy * Concurrent medication for coexisting condition is allowed, as long as dose and pattern of administration is held constant during study --Patient Characteristics-- * Renal: Urinary porphobilinogen excretion of at least 20 mg every 24 hours * Other: Not pregnant Fertile female patients must use effective contraception during and at least 6 months before study At least 1 month since any symptoms of disease No concurrent acute hemorrhagic disorder such as: Gastrointestinal bleeding Intracerebral hemorrhage No known hypersensitivity to heme arginate, tin mesoporphyrin, another heme preparation, or related heme analogue No other condition that may increase risk to patient