Spironolactone can be effective in about a day. Spironolactone is a potassium-preserving diuretic commonly used in clinical practice. Spironolactone can bind to aldosterone receptors in the epithelial cells of the distal tubules and collecting ducts of the kidney, which can inhibit the K-Na exchange effect of aldosterone. So that K ions are retained, while Na ions and Cl ions are excreted in increased amounts, producing a diuretic effect. It is commonly used clinically for: hypertension, cirrhosis ascites, renal edema and other diseases. Because it is easy to lead to the occurrence of hyperkalemia when taken alone, it is often used in combination with thiazide diuretics such as hydrochlorothiazide, which can maintain blood potassium and enhance the diuretic effect, so this drug is prohibited for patients with high blood potassium. If the use of spironolactone is the occurrence of hyperkalemia, gastrointestinal reactions, hyponatremia, allergic reactions and other adverse reactions, follow the doctor’s advice to reduce the dosage or replace other drugs. In the application, spironolactone belongs to the long-acting diuretics, the effect is slower, about one day to take effect, the maintenance effect is longer, the effect can be maintained for 2 to 3 days, can be used for a long time to assist in lowering blood pressure. In the use of such drugs need to be rationally used under the guidance of the doctor.