Classical and Modern Drug Treatments for Leishmaniasis

Abstract

Leishmaniasis is a complex disease caused by intracellular parasites of the genus Leishmania spp. According to the World Health Organization (WHO) there are over one billion people at risk of infection. In more than 95% of the cases, visceral leishmaniasis is fatal if not treated. Antimonials are used as the first-choice drug to control leishmaniasis; however, their use is limited owing to high toxicity, parenteral administration, and monitoring throughout the entire treatment. The resistance to antimonials, most notably in India, has become a serious problem and has led to use of alternative drugs such as amphotericin B, pentamidine, and miltefosine, which are considered to be second-choice drugs. The lipid formulations of amphotericin B were successfully developed to decrease toxicity; miltefosine is an oral drug that succeeded in India; however, the efficacy of this drug in other countries still shows conflicting results. Drug combinations have been tested to minimize side effects and decrease duration of treatment and cases of drug resistance. There are a few optional therapies, but no vaccines against human leishmaniasis until now. In this review, we discuss current and new drugs and the priority of establishing new strategies for the treatment of leishmaniasis.