Accumulation of pentavalent antimony in patients of visceral leishmaniasis

ABSTRACT

Fourteen Bangladeshi patients with parasitologically proven visceral leishmaniasis were randomly divided into two groups one group [eight patients] received pentavalent antimony [sodium stibogluconate], 20mg per Kg body weight per day intravenously by single injection for 20 days; second group [six patients] the same amount of drug per day in two divided doses for 20 days. Urine samples of each patient were collected throughout the treatment and the total amount of pentavalent antimony was calculated. Almost the whole amount of injected antimony was excreted in the urine in single dose regimen. On the other hand, about 20% of the injected drug was accumulated within the body in two divided dose regimen. Next we studied which tissues were involved in the accumulation of antimony. Using guinea pig, it was found that antimony was accumulated mainly in the spleen and liver. The antimony accumulated in the spleen or liver were only in the pentavalent form. There were no conversion of pentavalent antimony into trivalent one in those tissues. It is concluded that divided dose administration of pentavalent antimony, compared to single dose administration, is unsafe, due to the risk of toxic effects through accumulation