Porphyria Educational Services
PORPHYRIA EDUCATIONAL SERVICES Bulletin Vol. 1 No. 30 July 25, 1999
Focus: Hematin Panhematin or Hematin for short, is used for intervention therapy in acute attacks of porphyria. Hematin is often administered after 24 to 30 hours of glucose has been administered and has not brought an acute attack under control.
Panhematin is manaufactured by the Abbott Laboratories. Hemin for injection is an enzyme inhibitor derived from processed red blood cells.This used for injection was known previously as hematin.
The term hematin has been used to describe the chemical reaction product of hemin and sodium carbonate solution. Hemin is an iron containing metalloporphyrin. Chemically hemin is represented as chloro (7,12-diethenyl-3,8,13,17-tetramethyl-21H,23H-porphine-2,18-dipropanoato (2-)-N21,N22,N23,N24) iron for all of porphyrics with a chemistry background!
The hematin is a sterile, lyophilized powder suitable for intravenous administration after reconstitution. The bad "rap" that hematin has been given by many physicians is that it will cause coagulation problems in patients, leaving them with blood clots and possible pulmonary emboli.
The reasons for this concern is that often this powder substance has not been properly mixed, and also because it has not been used within a short time of mixing. It is vital that the substance be properly mixed and that it is immiediately administered by iv infusion.
Each dispensing vial of hematin contains the equivalent of 313 mg hemin, 215 mg sodium carbonate and 300 mg of sorbitol. The pH may have been adjusted with hydrochloric acid; the product contains no preservatives. When mixed as directed with Sterile Water for Injection, USP, each 43 ml provides the equivalent of approximately 301 mg hematin (7 mg/ml).
Outside of the United States a purer refined heme substance known as heme arginate is readily used. It is currently used in clinical trials at the University of Texas Medical School in Galveston, TX, by Dr. Karl Anderson, a leading porphyria researcher. No expected date for FDA approval in the U.S. has been announced.