The side effects of beta-blockers are as follows: 1. sinus bradycardia, atrioventricular block in severe cases, and hypotension and even cardiogenic shock in the most severe cases. 2. bronchial asthma or respiratory dysfunction. 3. heart failure or deterioration of cardiac function when taking large amounts of beta-blockers, and activation of endogenous beta receptors when combined with digoxin. 4. It can cause central nervous system side effects, such as insomnia, excessive dreaming, and plant nervous system dysfunction.5. It can cause withdrawal syndrome, and sudden discontinuation of beta-blockers can induce angina pectoris in patients who have been taking beta-blockers for a long time.6. It can lead to peripheral vasoconstriction, chills in the limbs, and intermittent rash.7. Betalac can also cause hepatic and renal insufficiency under long-term use.8.