Fimasartan, also known as Kanarb, is a drug used to treat heart failure. It works by blocking AT1 receptors in the renin-angiotensin-aldosterone system, thereby lowering blood pressure. It is synthesized through a thioamidation reaction and has a half-life of 7 to 10 hours. It is rapidly absorbed and most is eliminated unchanged in bile, with less than 3% eliminated in urine. Its structure allows optimal activity through features that mimic angiotensin II and provide lipophilicity for absorption.