Lijunning Metoprolol Tartrate Sustained‑Release Tablets (Ⅱ)

1. Indications and Usage
Hypertension and Angina: Indicated for the treatment of hypertension and angina pectoris.
2. Dosage and Administration
Standard Dose: The usual dosage is 100 mg once daily in the morning.
Administration: Dosage should be individualized. It must be administered orally.
3. Mechanism of Action
Beta-Blockade: This drug belongs to Class II beta-adrenergic blocking agents with selective beta-1 blocking activity.
Cardiovascular Effects: It has no partial agonist activity or membrane-stabilizing effects. It reduces heart rate, myocardial contractility, and blood pressure.
4. Safety and Warnings
Contraindications: Contraindicated in patients with marked bradycardia (heart rate <45/min), cardiogenic shock, severe or acute heart failure, impaired peripheral perfusion, second- or third-degree AV block, sick sinus syndrome, and severe peripheral vascular disease.
Discontinuation: Therapy should generally be discontinued gradually over 7-10 days. Abrupt cessation may exacerbate angina or induce myocardial infarction.
Anesthesia: The drug should be discontinued at least 48 hours before surgery requiring general anesthesia.
5. Adverse Reactions and Clinical Research
Cardiovascular: Bradycardia, conduction blocks, hypotension, worsening heart failure, and peripheral vasospasm (e.g., cold extremities).
Central Nervous System: Fatigue and dizziness (approx. 10%), depression (approx. 5%), headache, insomnia, and rarely hallucinations.
Gastrointestinal: Nausea, dyspepsia, and diarrhea (approx. 5%).
6. Drug Interactions
CYP Inhibitors: Concurrent use with cimetidine or pre-treatment with quinidine can increase metoprolol blood concentrations.
Other Agents: Caution is advised with drugs that further reduce heart rate or blood pressure.
7. Pharmaceutical Information
Active Ingredient: Metoprolol Tartrate.
Chemical Formula: (C15H25NO3)2·C4H6O6.
Molecular Weight: 684.82.
Appearance: White or off-white tablets with film coating.
Storage: Protect from light. Store in a dry place at 10-30°C in a tightly closed container.