Parasitic infections such as malaria, schistosomiasis, trypanosomiasis and onchoceriasis are the scourge of the tropical countries. Many of the drugs used for the treatment of tropical parasitic infections were introduced more than 30 years ago. Most of these drugs are toxic and have complicated dosage regimens, but, because of the low economic incentive, pharmaceutical companies have shown little interest in developing new drugs to control diseases prevalent in developing countries.; However, there has been notable progress in research into parasitic diseases and a number of important drugs...