Secondary prevention of hypertension refers to oral medications to control blood pressure in the normal range. 1. calcium antagonists, such as nifedipine extended-release tablets, nicardipine, felodipine, nifedipine controlled-release tablets, etc. 2. ACEI or ARB drugs, such as benazepril, enalapril, valsartan, coxsartan, etc. 3. beta-blockers, metoprolol, metoprolol succinate 4. diuretics, such as torasemide, hydrochlorothiazide, spironolactone, etc. Depending on the severity of blood pressure, patients can apply the above drugs alone or in combination to control blood pressure in the normal range, usually below 140/90 mmHg.