Ebselen (also called PZ 51, DR3305, and SPI-1005), is a synthetic organoselenium drug molecule with anti-inflammatory, anti-oxidant and cytoprotective activity. It acts as a mimic of glutathione peroxidase and can also react with peroxynitrite. It is being investigated as a possible treatment for reperfusion injury and stroke, hearing loss and tinnitus, and bipolar disorder. Additionally, ebselen may be effective against Clostridioides difficile infections and has been shown to have antifungal activity against Aspergillus fumigatus.