Betalucil is also known as Metoprolol, and Metoprolol is subdivided into Metoprolol Tartrate and Metoprolol Succinate, the maximum dosage is not explicitly mentioned in the instruction manual, which is mainly because the maximum dosage of Metoprolol is determined according to the disease that the patient suffers from. Metoprolol tartrate is 25mg per tablet and the maximum dose for treating high blood pressure is 100-200mg/day, while metoprolol succinate is 47.5mg per tablet and the maximum dose for treating high blood pressure is 190mg/day. The maximum dose of metoprolol tartrate for the treatment of heart failure is 300-400mg/day, while metoprolol succinate may be increased gradually to a maximum dose of 190mg/day in patients with heart failure. Metoprolol is used clinically for the treatment of hypertension, angina pectoris, myocardial infarction, and hypertrophic cardiomyopathy. Common adverse effects include fatigue, headache and dizziness, bradycardia, abdominal pain, nausea and vomiting, and diarrhea. It is contraindicated in patients with hypotension, bradycardia, hepatic or renal failure, and bronchial asthma. If patients want to use Metoprolol for treatment, it is recommended to standardize the use of medication under the guidance of a doctor, do not increase the dosage privately, so as not to cause adverse effects.