Treatment of visceral leishmaniasis with amphotericin B colloidal dispersion

Amphotericin B is an effective antileishmanial agent whose use is limited by drug toxicity. The development of less toxic, lipid encapsulated formulations of amphotericin B as antimycotic agents has made these formulations available for testing against visceral leishmaniasis, a disease ideally suited for 'liposomal' therapy since the parasites are only found within reticuloendothelial macrophages. In phase II experiments of Amphotericin B Colloidal Dispersion (ABCD) for Brazilian kala-azar, 10 of 10 patients were cured with 2 mg/kg/day for 10 days; 9 of 9 patients were cured with 2 mg/kg/day for 7 days; 9 of 10 patients were cured with 2 mg/kg/day for 5 days. The ability to cure 90% of kala-azar patients with a regimen of merely 5 days is remarkable considering that 20-40 days of treatment with pentavalent antimonials and a 28-40 day course of (every-other-day) amphotericin B desoxycholate therapy are otherwise needed. Although ABCD did frequently cause a syndrome of fever and respiratory distress during infusion for children less than 6 years of age, the virtual absence of kidney toxicity was striking.