Nitisinon er en kompetitiv hæmmer af 4- hydroxyfenylpyruvatdioxygenase, et enzym, der går forud for fumarylacetoacetathydrolase i tyrosinkatabolismens vej.
Nitisinone is a competitive inhibitor of 4-hydroxyphenylpyruvate dioxygenase, an enzyme which precedes fumarylacetoacetate hydrolase in the tyrosine catabolic pathway.