Visceral leishmaniasis in the BALB/c mouse: sodium stibogluconate treatment during acute and chronic stages of infection.

The effect of initiating drug treatment (free, liposomal or surfactant vesicle forms of stibogluconate) at different times post-infection in Leishmania donovani infected BALB/c mice was studied. It was found that free stibogluconate therapy was less effective at the later stages of infection, i.e. there was a right shifting of the dose response curve. Treatment with either carrier form of the drug was less sensitive to the length of infection so that the benefit obtained by using this form of the drug dramatically increased over the course of infection. The liposomal and surfactant vesicle forms of the drug were equally effective and they were always more suppressive than the free drug. It is proposed that the successful therapeutic outcome of drug treatment is dependent on the interaction of the innate antileishmanial activity of the drug and a host factor(s), which can either augment or reduce the inherent activity of the drug.