Current strategies in the search for novel antiparasitic agents

The market for antiparasitic products comprises the largest segment for sal es of livestock and companion-animal healthcare agents. Despite the availab ility of highly effective, broad-spectrum agents, there remains a need for safer, more convenient and more environmentally friendly products that will overcome the ever-present threat of resistance development. The very high cost of discovering and developing a new drug, especially for use in livest ock, is reflected in the limited number of new classes of antiparasitic age nt launched on the market. New strategies are being adopted to minimise the cost of discovering potential drug candidates by maximising the chance of identifying a useful target mechanism of action and by speeding the time to discover and optimise a lead structure. These rely heavily on new technolo gies in target identification, screen development and lead optimisation. Ex amples of these will be discussed and speculation made about the possible f actors that could influence the future shape of antiparasitic control. (C) 1998 Australian Society for Parasitology. Published by Elsevier Science Ltd . All rights reserved.