A toluidine derivative and nonsteroidal antiandrogen that is structurally related to bicalutamide and nilutamide. Flutamide and its more potent active metabolite 2-hydroxyflutamide competitively block dihydrotestosterone binding at androgen receptors, forming inactive complexes which cannot translocate into the cell nucleus. Formation of inactive receptors inhibits androgen-dependent DNA and protein synthesis, resulting in tumor cell growth arrest or transient tumor regression. Check for "https://www.cancer.gov/about-cancer/treatment/clinical-trials/intervention/C509" active clinical trials using this agent. ("http://ncit.nci.nih.gov/ncitbrowser/ConceptReport.jsp?dictionary=NCI%20Thesaurus&code=C509" NCI Thesaurus)