Tolol tablets should be metoprolol tablets. The drug is used to treat high blood pressure and angina pectoris. In its use, you need to pay attention to possible adverse reactions such as conduction block. Metoprolol has the ability to selectively block cardiac beta receptors, thus exerting the effects of slowing down the heart rate, decreasing myocardial contractility, decreasing autoregulation, and increasing atrioventricular conduction time. It is commonly used clinically in the treatment of hypertension, hypertrophic cardiomyopathy, aortic coarctation, partial arrhythmias, hyperthyroidism, and cardiac neurosis. In the use of the drug may occur heart rate slowing, conduction block, blood pressure decreased, fatigue heart, stomach pain and other symptoms of adverse reactions, it is recommended to go to the hospital to inform the physician, the physician symptomatic treatment or adjust the dose of the drug. The use of the drug is prohibited in the presence of hypotension, bradycardia, hypotensive shock, acute heart failure, poor perfusion of peripheral circulation due to peripheral vascular disease, high degree of atrioventricular block, suspected acute myocardial infarction, etc. The drug is contraindicated in pregnant and lactating females because it may cause fetal or neonatal developmental retardation. Metoprolol needs to be used under the supervision of a clinician.