Trypanocidal drugs suramin

Suramin is a colorless dye that evolved from Ehrlich s early work with azo dyes such as Trypan Red that cured mice infected with trypanosomes (Ehrlich and Shiga, 1904). It has therefore been viewed as the first synthetic chemotherapeutic drug (it was inactive in humans). A decade later, suramin, which is, however, trypanocidal in humans, was introduced. It is still in use today for this purpose. Even though the drug has since been shown to inhibit various enzyme systems in parasitic protozoa and worms such as filaria (see avermectin later), its mechanism of action and basis of selective toxicity has still not been elucidated. 

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