Lung fluke infections, drugs

Bithionol (Fig. 7-10) is useful for the treatment of Fasciola hepatica (sheep liver fluke) and Paragonimus westermanii, the lung fluke. It is highly effective. The drug impairs egg formation, uncouples oxidative phosphorylation, and chelates iron, possibly from crucial enzymes. None of these facts has been related to a molecular mechanism, which remains obscure. In any case, it would appear that PQ will likely replace this ftw-dichlorophenol as the drug of choice for these two fluke infections. 

Praziquantel (PQ) (Table 7-10), a pyrazinoisoquinoline, can be viewed as having evolved from mirasan by optimizing structural features of compound V (Fig. 7-14). For all intents and purposes it is the first really broad-spectrum anthelmintic that is effective against all schistosomes and most other flukes, such as liver, intestinal, and lung (see Table 7-9 for species). PQ is rapidly becoming the drug of choice for many of the preceding infections, as well as for the cestodes (tapeworms). 

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