tasosartan tasosartan tasosartan is an angiotensin ii receptor antagonist. tasosartanclinical datapregnancycategory n/a atc codec09ca05 (who) legal statuslegal status withdrawn identifiers iupac name 2,4-dimethyl-8--5,8-dihydropyridopyrimidin-7(6h)-one cas number145733-36-4 ypubchem cid60919iuphar/bps6898drugbankdb01349 ychemspider54890 nunii48g92v856hcomptox dashboard (epa)dtxsid40163148 chemical and physical dataformulac23h21n7omolar mass411.469 g·mol−1 ny (what is this?) (verify) it was withdrawn from fda review by the manufacturer after phase iii clinical trials showed elevated transaminases (a sign of possible liver toxicity) in a significant number of participants given the drug.