Benadryl and Felodipine can be used in combination. The combination of Benadryl and Felodipine is a common and effective method of treating essential hypertension in the elderly, but the specific use of the drug should be carried out in accordance with the medical advice of a specialized physician. 1. Benadryl: belongs to the angiotensin-converting enzyme inhibitor (ACEI), its antihypertensive effect is through the inhibition of angiotensin-converting enzyme, so that angiotensin Ⅱ generation is reduced, and at the same time inhibition of kininase so that the degradation of bradykinin is reduced, which is conducive to vasodilatation, so that the blood pressure is reduced. 2. Felodipine: it is a long-acting calcium channel blocker, which can inhibit the inflow of extracellular calcium ions through the cell membrane to the intracellular inflow, leading to a decrease in vascular resistance, and can be selected to dilate the arteries and make the blood pressure drop. Felodipine also reduces coronary vascular resistance by dilating the arteries and small arteries in the epicardium, increasing coronary blood flow and myocardial oxygen supply, thus reducing the occurrence of diabetic cardiovascular disease complications. Some patients may experience adverse reactions such as dizziness and diarrhea after taking Benadryl; it is contraindicated in those who are allergic to this drug. Adverse reactions such as fatigue and fever may occur after taking Felodipine, which is contraindicated in pregnant women and those who are allergic to this drug. Clinical treatment of hypertension in the elderly is often used in combination with two drugs, not only to increase the effect of lowering blood pressure, but also significantly reduce the cough or edema and other adverse reactions. Specific use should be taken according to the doctor’s instructions, to avoid the adverse consequences of self-medication.