Antimonials and Resistance
Antimonials have been known since ancient times as medicine. It is called as antimonials because antimony (Sb)—a metalloids belonging to group XV of periodic table of element present in this compound. Sb is present in trivalent Sb(III) and pentavalent Sb(V) form. In the beginning of twentieth century, Tartar Emetic, an organic trivalent form of antimony was used for treatment of sleeping sickness and Gaspar Vianna introduced the drug for the treatment of MCL in 1912. The activity of Antimonials against various clinical form of leishmaniasis was soon discovered. Since, Tartar Emetic was highly toxic for human, new less toxic and more effective Antimonials were developed and evaluated. Pentavalent [Sb(V)] salts were found to be less toxic to mammal than trivalent [Sb(III)] salts. By the end of 1940s pharmaceutical research produced the current drug in use; the closely related organic pentavalent antimonial compounds Sodium antimony Gluconate (SAG) and Meglumine antimonite.