<p>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.</p>