Phenothiazine antipsychotics block dopamine receptors (DA2) in the mesolimbic system and mesocortical pathways, and have blocking effects on dopamine (DA1) receptors, 5-hydroxytryptamine receptors, M-type acetylcholine receptors, and α-adrenaline receptors. At low doses, they inhibit dopamine receptors in the medulla oblongata emetic chemoreceptor area, and at high doses, they directly inhibit the vomiting center to produce an antiemetic effect, inhibit the body temperature regulation center to lower body temperature, block peripheral α-adrenaline receptors to cause vasodilation and a decrease in blood pressure, and have a certain effect on the endocrine system.

This product is an anti-anemia drug. Vitamin B12 participates in methyl conversion and folic acid metabolism in the body, and promotes the conversion of 5-methyltetrahydrofolate into tetrahydrofolate. When it is deficient, it leads to DNA synthesis disorders and affects the maturation of red blood cells. This product also promotes the conversion of methylmalonic acid into succinic acid and participates in the tricarboxylic acid cycle. This effect is related to the synthesis of nerve myelin lipids and the maintenance of the integrity of myelinated nerve fiber function. The nerve damage caused by vitamin B12 deficiency may be related to this.

As a histamine H1 receptor antagonist, this product can counteract the capillary dilation caused by allergic reactions, reduce the permeability of capillaries, and relieve wheezing caused by bronchial smooth muscle contraction. This product has a long-lasting antihistamine effect and also has a significant central inhibitory effect, which can increase the effects of anesthetics, analgesics, hypnotics and local anesthetics. This product is mainly metabolized in the liver.

1. Treat metabolic acidosis. This product increases the concentration of carbonate in plasma and neutralizes hydrogen ions, thereby correcting acidosis. 2. Alkalinize urine. As the pH value increases after the concentration of bicarbonate in urine increases, uric acid, sulfonamide drugs and hemoglobin are not easy to form crystals or aggregate in urine. 3. Antacid. Oral administration can quickly neutralize or buffer gastric acid without directly affecting gastric acid secretion. Therefore, the pH in the stomach increases rapidly to relieve the symptoms caused by high gastric acid.

Sulfonamides are the earliest type of artificially synthesized broad-spectrum antibacterial drugs used. The minimum effective concentration in the blood is 5 mg/100 ml, and 10-15 mg/100 ml is required for severe infections. They are effective against most Gram-positive bacteria and some Gram-negative bacteria. Sulfonamides exert their antibacterial effects by competing with PABA for dihydrofolate synthetase, hindering the synthesis of folate in sensitive bacteria. Sulfonamides have no effect on already synthesized folic acid, so the effect occurs slowly. Bacteria that can utilize exogenous folic acid are not sensitive to sulfonamides. Livestock and poultry cells can directly utilize folic acid, so they are not easily affected by sulfonamides blocking folic acid synthesis.