Diphenhydramine is a calcium channel blocker, and there are two types of antihypertensive drugs in this class, including dihydropyridines and non-dihydropyridines. Dihydropyridines mainly include nifedipine, while non-dihydropyridines include verapamil and diltiazem, as well as diphenhydramine. The long-acting ones include amlodipine, levo-amlodipine, lacidipine, lercanidipine, felodipine extended-release tablets and nifedipine controlled-release tablets. The short-acting ones are nifedipine and nimodipine, which are relatively fast-acting and have a strong antihypertensive effect. And there is no obvious effect on blood sugar and blood lipids, and the antihypertensive effect is better for the elderly, and after long-term application, it can have anti-atherosclerotic effect. Its adverse reactions mainly include increased heart rate, facial flushing, headache, lower limb edema, etc., especially the short-acting diphenhydramine class, adverse reactions are more common.