The generic name of Betalucil is Metoprolol, and Metoprolol cannot be stopped after taking half a tablet. Metoprolol cannot be stopped suddenly after taking half a tablet, because once the drug is suddenly stopped, it will cause a reflex increase in heart rate, leading to discomfort and affecting normal recovery. If patients with coronary heart disease suddenly stop using the drug, it may also induce angina attacks, so the need to stop using the drug, need to be under the guidance of the doctor. Metoprolol is a commonly used beta-blocker that can be used to lower blood pressure, slow the heart rate, improve the long-term prognosis of patients with heart failure or heart attack, and improve the remodeling of the heart muscle. Patients may experience adverse symptoms such as abdominal pain, nausea, and vomiting, accompanied by dizziness and headache after using the drug. Attention to diabetes, hyperthyroidism and pregnant women with caution. 2,3 degrees of atrioventricular block, severe bradycardia and the ineffectiveness of digitalis in patients with heart failure is contraindicated; on the obvious bradycardia, Ⅱ ~ Ⅲ degrees of atrioventricular block, cardiogenic shock and severe heart failure is contraindicated. It should not be used in patients with decompensated heart function. Need to take the drug or stop using the drug, should be under the guidance of a doctor, not blindly use the drug on their own.