Some diuretics can cause hypokalemia, such as furosemide and hydrochlorothiazide, so they need to be standardized in accordance with medical advice. Commonly used diuretics include the following: 1. Medullary diuretics: Commonly used are furosemide, etanercept, this drug has a fast and strong effect, usually 5-10min can produce diuretic effect, 1h to reach the peak, usually after intravenous injection use. It is suitable for acute left heart failure or intractable heart failure, after a large amount of diuresis may cause electrolyte disorders, thus appearing hypokalemia. 2. Thiazide diuretics: Commonly used are hydrochlorothiazide, indapamide and so on, which are oral drugs, and the efficacy can be seen in 1h after taking the drugs, and it is easy to produce hypokalemia after taking them for a long period of time, so it is necessary to pay attention to replenish potassium. 3. Potassium-preserving diuretics: Such as spironolactone, aminopterin, it has the role of sodium retention of potassium, diuretic effect is not too strong when used alone, but can be combined with other diuretic drugs to reduce the occurrence of hypokalemia. 4. Carbonic anhydrase inhibitors: Such as acetazolamide, the diuretic effect is relatively mild. Some diuretics can cause hypokalemia, so they should be used in accordance with the doctor’s instructions to avoid blindly using the drugs on their own, which may produce adverse effects.