Short-course, low-dose amphotericin B lipid complex therapy for visceral leishmaniasis unresponsive to antimony

Visceral leishmaniasis (kala-azar) is a worldwide, disseminated intracellular protozoal infection for which prolonged, conventional therapy with pentavalent antimony has become increasingly less effective.

To determine the efficacy and minimal effective dose of short-course therapy with amphotericin B lipid complex in visceral leishmaniasis.

A randomized, open-label study.

Inpatient kala-azar treatment unit in the state of Bihar in northeast India, where visceral leishmaniasis is endemic.

60 patients with active infection who had not responded to or who had relapse after receiving conventional (> 30 days) treatment with pentavalent antimony.

Intravenous amphotericin B lipid complex was given once daily for 5 consecutive days by 2-hour infusion. Patients were randomly assigned to receive 1, 2, or 3 mg/kg of body weight per day (total doses of 5, 10, or 15 mg/kg, respectively).

Clinical and parasitologic responses (the latter were measured by parasite density score of the splenic aspirate) were determined 14 days after treatment. Definitive responses were assessed 6 months after treatment according to clinical outcomes and findings on examination of bone marrow aspirate.

All 60 patients responded to 5 days of treatment. Fourteen days after therapy, all patients had parasite-free splenic aspirates and were considered to have an apparent clinical and parasitologic response. Six months after therapy, definitive responses were documented in 16 of 19 (84% [95% Cl, 60% to 97%]), 18 of 20 (90% [Cl, 68% to 99%]), and 21 of 21 (100% [Cl, 84% to 100%]) patients who received total doses of 5, 10, and 15 mg/kg, respectively.

Short-course therapy with low-dose amphotericin B lipid complex is effective for visceral leishmaniasis and is an important therapeutic alternative in the management of this serious intracellular protozoal infection.