Candesartan cilexetil is a kind of prodrug being hydrolyzed to candesartan during absorption from the gastrointestinal tract. It appears as a white or off-white powder with a molecular weight of 610.67. It is soluble in methanol but insoluble in water. It is a kind of selective AT1 subtype angiotensin II receptor antagonist, mainly used for the treatment of hypertension and heart failure. Candesartan cilexetil takes effects through selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland, further blocking the vasoconstrictor and aldosterone-secreting effects of angiotensin II. Therefore, its mode of action is not through interfering with the pathways for angiotensin II synthesis. Candesartan cilexetil may lead to various kinds of adverse reactions including headache, back pain, dizziness, upper respiratory tract infection, pharyngitis, rhinitis, bronchitis, coughing, sinusitis, nausea, abdominal pain, diarrhea, vomiting, arthralgia and albuminuria. It should be warned that candesartan cilexetil might have remarkable fetal toxicity. Therefore, upon pregnancy, candesartan cilexetil should be discontinued. It could also cause hypotension for heart-failure patients.