The possible reasons for taking antihypertensive drugs, such as felodipine extended-release tablets, and the blood pressure does not fall to the desired level include higher basal blood pressure and secondary hypertension, as follows: 1. Higher basal blood pressure: For patients with initial diagnosis of hypertension grade 2 or higher, it is recommended to initially combine two or more antihypertensive drugs with different mechanisms of action for treatment. The felodipine extended-release tablets are calcium antagonists and often need to be combined with renin angiotensin-converting enzyme inhibitors, renin angiotensin II receptor antagonists, or beta-blocker diuretics to control blood pressure, and pay attention to therapeutic lifestyle improvements. 2, secondary hypertension: It should be noted that for taking antihypertensive drugs to lower blood pressure is not satisfactory, it is necessary to exclude secondary hypertension factors The blood pressure can be controlled smoothly by giving the appropriate treatment, including renal hypertension, renal vascular hypertension, endocrine hypertension, and the possibility of sleep apnea hypoventilation syndrome. In addition, it is important to pay attention to the type of blood pressure fluctuations, and adjust the time and method of taking antihypertensive drugs if necessary.