Towards a Strategic Plan for Research to Support the Global Program to EIiminate Lymphatic FiIariasis: Summary of Immediate Needs and Opportunities for Research on Lymphatic Filariasis. 2.2 Essential tools – Drugs and Clinical Drug Trials

Abstract

A series of advances during the past decade transformed LF from a neglected disease of poor countries into a disease now recognized as potentially eradicable. Principal among the reasons for these advances were the identification of ivermectin and albendazole as new, effective anti-filarial agents and the discovery of new virtues for an old anti-filarial drug, DEC (i.e., its single-dose efficacy and macrofilaricidal action). These discoveries were essential for the subsequent creation of the Global Program to Eliminate LF,1 whose very basis is the large-scale use of DEC, ivermectin (Mectizan�; Merck and Co., Inc., Rahway, NJ) and albendazole. Indeed, in many endemic countries literally millions of tablets of these drugs are distributed over a few short days each year (often on a single day), making GPELF the largest chemotherapy program ever undertaken. Currently it is just these three drugs that are available for use in single-dose, annual MDA programs. Albendazole is co-administered with ivermectin in areas of Africa and Yemen where LF and onchocerciasis are co-endemic. For all other LF-endemic regions, albendazole is co-administered with DEC. At the recommended dose levels, none of the drugs is completely macrofilaricidal, although all appear to inflict some lasting damage to adult worms. Both DEC and ivermectin kill mf efficiently; albendazole, on the other hand, has no direct effect on mf, but rather appears to suppress embryogenesis in the adult female worm. An alternative treatment strategy involving the use of DEC as a fortificant in table/cooking salt for a period of 1−2 years is currently used in just one country, but was a mainstay of the earlier, successful LF elimination program in China