Diphenhydramine antihypertensive drugs refer to dihydropyridine calcium channel blockers, which can be categorized into long-acting and short-acting according to the duration of the drug’s action. Long-acting ones include amlodipine, levamlodipine, felodipine extended-release tablets and nifedipine controlled-release tablets. Short-acting ones are mainly nifedipine and nimodipine. Adverse effects of dihydropyridine calcium channel blockers mainly include cardiovascular-related and others. Among them, the vascular-related adverse reactions are mainly because of the relatively rapid rate of blood pressure lowering, which is easy to cause a reflex increase in heart rate, and clinically, patients will produce symptoms of palpitations. Secondly, because of the relatively large degree of vasodilatation, some patients will experience significant headache and head swelling. Due to the short-acting type of rapid lowering of blood pressure, so the adverse reactions are also more. Other adverse reactions include anterior tibial edema, gingival hyperplasia, and constipation or alopecia, which are usually more common in patients who have been using the drug for a long time. Therefore, in the clinical use of dihydropyridine calcium channel blockers for the treatment of hypertension, in addition to the choice of short-acting or long-acting drugs according to the needs of the patients, but also to consider the patient’s tolerance of adverse effects, especially cardiovascular adverse effects, to avoid adverse consequences. If there is any discomfort, consult a doctor in time, and follow the doctor’s instructions to choose the appropriate treatment and medication for the patient.