In clinical practice, potassium chloride extended-release tablets and potassium chloride injection are usually used for potassium supplementation, both of which can cause hyperkalemia, such as weakness, fatigue, numbness of hands, feet, mouth and lips, respiratory difficulties, cardiac arrhythmia, conduction block, and even cardiac arrest and other adverse reactions. Potassium chloride extended-release tablets can also have nausea and vomiting, abdominal pain, skin rash, etc.; potassium chloride injection can irritate the venous lining causing pain and even phlebitis. Potassium is the main cation in cells, and the normal intra- and extracellular potassium ion concentration and concentration difference have a close relationship with certain cellular functions, such as carbohydrate metabolism, glycogen storage, protein metabolism, nerve and muscle excitability and conductivity. Both potassium chloride extended-release tablets and potassium chloride injection can be used for the prevention and treatment of hypokalemia caused by various reasons, in addition to potassium chloride injection, it can also be used for the treatment of tachyarrhythmia, frequent and polygenic premature beats caused by digitalis intoxication. Before using potassium supplementation drugs, it is necessary to find out whether there is any potassium deficiency, and pay attention to whether the patient’s urine output and renal function are normal, and whether there is any disturbance in the acid-base balance of body fluids. After the use of the drug, the patient’s blood potassium, magnesium, sodium, calcium ion concentration, electrocardiogram, acid-base balance of body fluids, as well as renal function and urine output and other indicators should be closely monitored. In case of abnormality, it is necessary to stop the drug according to the doctor’s instruction. These two drugs are contraindicated in the following cases: hyperkalemia; acute and chronic renal insufficiency; use of potassium-preserving diuretics. In addition, the drug is contraindicated in patients who are allergic to potassium chloride injection. If you need to use the above drugs, please take the drugs under the guidance of the doctor and strictly follow the doctor’s instructions, and do not use the drugs on your own.