Hematin toxicity in rats

The toxicity of intravenously administered hematin (3.4 and 6 $\text{mg}\text{100 g}$) was investigated in rats, where an LD₅₀ of 4.32 $\text{mg}\text{100 g}$ was computed, with 95% confidence limits of 5.40 and 3.46 $\text{mg}\text{100 g}$. At toxic levels (4 $\text{mg}\text{100 g}$) the rats showed a drop of blood pressure, hemorrhages and renal failure, whereas lower doses were well tolerated. This study indicates a possibly wide therapeutic margin of safety, when compared to the therapeutic use of hematin on porphyric patients.