Betalac is a beta-blocker, which has certain side effects and hazards when taken for a long time.1. Betalac will slow down the heart rate after long-term application, accompanied by conduction block, and patients will have lowered blood pressure, and for patients with obvious heart failure in the past, there will be patients with aggravated heart failure if they take Betalac for a long time.2. Patients will have peripheral vasospasm and lead to cold extremities, or patients will have a fine and untouchable pulse.3. The patient may experience peripheral vasospasm, resulting in cold extremities, or the patient may have a fine, unpalpable pulse. 3. long-term use of betalactam may also cause irritation of the digestive system, such as epigastric discomfort, nausea, vomiting, etc. 4. for the nervous system, symptoms such as lethargy and insomnia may also occur.