Olmesartan and candesartan are commonly used antihypertensive drugs, but because of their pharmacological mechanisms are different, so the type of hypertension is also different, and its effect is also lack of comparability. The main ingredient of olmesartan ester is olmesartan ester, which is absorbed and hydrolyzed through the human gastrointestinal tract and converted into olmesartan, which selectively antagonizes angiotensin II1 type 1 receptor, thus controlling blood pressure. Patients may experience adverse reactions such as headache, dizziness, and diarrhea after taking the drug. For those who are allergic to olmesartan ester, this product needs to be disabled. The main component of Candesartan is Candesartan Ester, which is hydrolyzed to Candesartan in the human body to antagonize angiotensin II type 2 receptor and inhibit the adrenal gland’s ability to secrete aldosterone, so as to play a role in lowering blood pressure. This product is mostly used in the treatment of essential hypertension. Patients taking the drug may experience adverse reactions such as acute renal failure and angioedema. For people with severe hepatic or renal insufficiency and pregnant women, candesartan needs to be contraindicated. Since both olmesartan ester and candesartan are prescription drugs, both need to be used under the guidance of a doctor. At the same time, during the medication, patients who experience discomfort still need to seek medical attention to avoid increased risks.