The digitalis group of drugs includes digoxin, digitalis toxin, trichosanthin C (cidilan) and toxic trichosanthin K. They are mainly used in patients with heart failure or rapid heart rate in atrial fibrillation. Digitalis drugs, namely cardiac glycosides, are a class of positive inotropic drugs with similar chemical structures and the same effects, but with different side chains and pharmacokinetic differences, which can be divided into long-acting, intermediate-acting and short-acting. Long-acting class of digitalis: digitalis toxin, tablets, high lipid solubility, good oral absorption, mostly metabolized by the liver after renal excretion, half-life of 3-7 days, so the action time is longer. Indications: Patients with chronic heart failure can be used to improve symptoms. Intermediate-acting digitalis: digoxin, tablet, good oral absorption, wide distribution, can pass the blood-brain barrier, oral antibiotics can increase the blood concentration of digoxin, 2/3 is excreted by renal metabolism, half-life is 33-36 hours, so the action time is shorter. Application: digoxin has slow onset and long duration of action, so it can be used to improve the symptoms of heart failure chest tightness and shortness of breath for a long time when chronic heart failure patients have chest tightness and shortness of breath, and it can be used to control heart rate and reduce the symptoms of palpitations when atrial fibrillation patients have rapid heart rate. Short-acting type of digitalis: Cidilan, poisonous trichothecene K, not absorbed orally, need to be applied intravenously, most of them are excreted in the original form through the kidneys, with fast action and short maintenance time. It is suitable for the cases of atrial fibrillation with heart failure and rapid heart rate, or acute heart failure where the application of metoprolol is limited and the heart rate needs to be controlled as soon as possible to reduce the symptoms. Digitalis drugs are divided into long-acting, medium-acting and short-acting preparations according to their pharmacokinetics. Different preparations have similar efficacy, and different preparations are applied at different times, but such drugs need to be applied under the guidance of professional doctors.