Antiparasitic drugs selective toxicity

Finally, in case of the GABA-antagonistic sesquiterpenoids treated in the last section, interesting new insights into the structure-activity- and especially structure-selectivity relationships were introduced. Recently discovered selective toxicity towards insects as well as helminths point towards the potential of such compounds as leads to new insecticides and antiparasitic drugs. 

Rational approaches to antiparasite chemotherapy utilize the principle of selective toxicity, which exploits biochemical and physiologic differences between parasite and host cells. Many antiparasitic agents target enzymes that are unique to—or indispensable to— parasites other drugs affect cellular functions common to both host and parasite cells (Table 52-2). 

Niridazole, a nitrothiazole, is another toxic drug that was selected from a drug development program. The drug has some effect on all three species however, it is primarily useful clinically against S. hematobium, especially in children. The antiparasitic effect is directly on the reproductive system disruption of and abnormal egg productions and... 

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