Stibogluconic acid (Sodium stibogluconate) is the pentavalent antimonial compound used to treat leishmaniasis and is only available for administration by injection. Sodium stibogluconate is sold in the UK as Pentostam (manufactured by GlaxoSmithKline). Sodium stibogluconate was granted orphan drug designation for the treatment of cutaneous leishmaniasis by the US FDA in January 2007. It is available in the United States only through the Centers for Disease Control. Sodium stibogluconate is indicated for the treatment of various types of a protozoal infection called leishmaniasis, which may result from sandfly bites in tropical and temperate parts of the world. It is also investigated for use/treatment in cancer. The mode of action of sodium stibogluconate is not clearly understood. In vitro exposure of amastigotes to 500 mg pentavalent antimony/ml results in a greater than 50% decrease in parasite DNA, RNA protein and purine nucleoside triphosphate levels. It has been postulated that the reduction in ATP (adenosine triphosphate) and GTP (guanosine triphosphate) synthesis contributes to decreased macromolecular synthesis. Sodium stibogluconate was shown to specifically inhibit type I DNA topoisomerase from Leishmania donovani through the inhibition of the unwinding and cleavage of the supercoiled plasmid pBR322, and to stabilize topoisomerase and DNA covalent complexes but not calf-thymus topoisomerase I and Escherichia coli DNA gyrase. Sodium stibogluconate is also a potent inhibitor of PTPases Src homology PTPase1 (SHP-1), SHP-2, and PTP1B but not the dual-specificity phosphatase mitogen-activated protein kinase phosphatase 1. Sodium stibogluconate combined with IFN-alpha-2b (IFN-α) inhibited solid tumor cell line growth in vitro, in vivo it was well tolerated and augmented cellular immune parameters.