Levels of these precursors are very high during attacks of acute intermittent porphyria and remain high in people who have repeated attacks. The precursors can form porphyrins, which are reddish in color, and other substances that are brownish. Therefore, the urine may be discolored, especially after standing in light. Such changes in urine color may lead a doctor to suspect porphyria. Treatment and Prevention Severe attacks of acute intermittent porphyria are treated with heme, which must be given intravenously.
Heme is available as hematin in the United States.
Another product, heme arginate, has fewer side effects but is still investigational. Heme is taken up in the liver, where it compensates for the reduced synthesis of heme. Blood and urine levels of delta-aminolevulinic acid and porphobilinogen are promptly lowered and symptoms improve, usually within several days. If treatment is delayed, recovery takes longer and some nerve damage may be permanent. Glucose given intravenously or a diet high in carbohydrates can also be beneficial, but these measures are less effective than heme.