There are two kinds of Metoprolol Tartrate Tablets and Metoprolol Succinate Extended-Release Tablets, the difference is mainly in the dosage form, duration of efficacy, dosing time and specifications. 1. Dosage form: Metoprolol tartrate is mostly flat tablets, because of its general solubility in water, it is difficult to prepare into a membrane-controlled sustained-release micro-pills, and it can be made into a skeleton sustained-release tablets that cannot be broken open; Metoprolol succinate sustained-release tablets utilize a multi-unit microcapsule technology, which wraps each pellet into an independent resident unit that can be broken open and taken. 2. Duration of drug effect: the half-life of flat tablets is about 3~5 hours, which needs to be taken 2~4 times a day, and the fluctuation of blood concentration is relatively large; extended-release tablets have a smoother and more lasting effect, and they are released at an almost constant rate for about 20h, so it is usually enough to take them once a day. 3. Dosing time: flat tablets are fat-soluble drugs, greatly affected by food, taking meals will increase its bioavailability, so it should be taken on an empty stomach; slow-release tablets due to a short period of time the blood concentration rises faster, it is recommended to take in the morning. 4. Specification: the specifications of plain tablets are 25mg, 50mg, 100mg, and the specifications of extended-release tablets are 47.5mg, 95mg. If the plain tablets are replaced by extended-release tablets, the dosage should be converted according to the doctor’s instruction, and you can’t change the medicine by yourself. There are no adverse reactions or contraindications to the use of Metoprolol, which should be taken under the guidance of a physician. Patients who have been taking Metoprolol for a long period of time should be guided by a physician to gradually reduce the dosage of Metoprolol until it is discontinued, as it is easy to stop taking Metoprolol suddenly.