Metoprolol is a selective beta-1 blocker, which means that lower doses are required to affect beta-1 receptors in the heart than to affect beta-2 receptors in peripheral vascular and bronchial sites. However, as the dose of metoprolol increases, its selectivity for beta-1 receptors decreases.

Metoprolol is a selective beta-1 blocker, which means that lower doses are required to affect beta-1 receptors in the heart than to affect beta-2 receptors in peripheral vascular and bronchial sites. However, as the dose of metoprolol increases, its selectivity for beta-1 receptors decreases.

It relaxes vascular smooth muscle, activates guanylate cyclase by releasing nitric oxide (NO), increases cyclic guanosine monophosphate (cGMP) in smooth muscle cells, thereby dilating peripheral arteries and veins, reducing venous return, left ventricular end-diastolic pressure, pulmonary capillary wedge pressure, peripheral vascular resistance, systolic arterial pressure and mean arterial pressure, increasing coronary artery perfusion and reducing myocardial oxygen consumption.

This product is a highly selective 5-HT3 receptor antagonist, which has a good preventive and therapeutic effect on nausea and vomiting caused by radiotherapy, chemotherapy and surgery. It inhibits the occurrence of nausea and vomiting by antagonizing the 5-HT3 receptors in the central chemoreceptor area and peripheral vagus nerve endings. This product has high selectivity and no side effects such as extrapyramidal reactions and excessive sedation.

This product is a H2 receptor blocker of the guanyl thiazole class, which has the characteristics of high affinity for H2 receptors, and has a significant inhibitory effect on gastric acid secretion, and has an inhibitory effect on basal secretion and the increase of gastric acid and pepsin caused by various stimuli. This product does not change the gastric emptying rate, does not interfere with pancreatic function, and has no adverse effects on the cardiovascular system and kidney function. This product is different from cimetidine, but it is similar to ranitidine, that is, long-term high-dose treatment does not cause adverse reactions of androgen antagonism such as male breast development, impotence, lack of sexual desire, and female breast pain, galactorrhea, etc. It has no teratogenic, carcinogenic, drug enzyme inhibitory and androgen inhibitory effects.

A non-addictive analgesic with strong analgesic, local anesthesia, cooling, antipyretic, anti-inflammatory and detumescent effects. Its analgesic effect is comparable to that of pethidine, but with a slightly slower onset and longer duration; its analgesic effect is 7 times that of the antipyretic analgesic aminopyrine.