Pre-clinical studies in murine models of ischaemia reperfusion injury (IRI) have demonstrated that the anti-inflammatory enzyme HO-1 is of interest as a potential target for therapeutic intervention. Heme arginate (HA) is a drug licensed for human use, as a treatment for acute porphyria. HA upregulates HO-1, and ameliorates IRI when given before injury in murine models of IRI. In Phase I clinical trials, HA has been shown to upregulate HO-1 and is well tolerated.