Purpose: Acute porphyria episodes are routinely treated with hematin, but side effects, including disturbances of hemostasis and peripheral thrombophlebitis, are associated with the compound's use. Thrombophlebitis is particularly troublesome in patients who require repeated administration of hematin, and may eventually lead to the placement of central venous lines or implantation of indwelling venous access ports. We undertook this study to determine whether only patients with porphyria experienced peripheral thrombophlebitis and disturbed hemostasis following administration of hematin, or if this was a general phenomenon that could also be observed in normal volunteers.
Subjects and methods: Hematin was administered intravenously in the doses customarily used in therapy of acute porphyria crises (4 mg/kg body weight) to nine normal male volunteers, who were screened by history, physical examination, routine blood cell counts, urinalysis, biochemical screening profile, and coagulation tests. Hemostasis tests were performed in each subject, and hematin concentrations were determined.
Results: Within the first 24 hours, the activated partial thromboplastin time was prolonged in all subjects (mean of 25 percent), the prothrombin time was increased in eight subjects (mean of 20 percent), and the thrombin time in five subjects rose (mean of 15 percent), whereas the concentration of circulating platelets decreased in three subjects (mean of 20 percent). In four subjects (45 percent), thrombophlebitis developed following hematin infusion.
Conclusion: Although hematin is frequently effective in the treatment of acute porphyria crises, it is often associated with abnormalities in coagulation and these effects also occur in normal volunteers.