Chloroquine mainly acts on erythrocytic schizonts, and after 48 to 72 hours, schizonts in the blood are killed. This product is ineffective against the infrared stage of Plasmodium vivax malaria, so it cannot cure Plasmodium vivax malaria. It can cure falciparum malaria. Chloroquine is ineffective against the infrared stage and has no direct effect on gametocytes, so it cannot be used for etiology prevention and interruption of transmission. The negatively charged 7-chloro group on its quinoline ring is close to the 2-amino group on DNA guanine, so that chloroquine is inserted between the two strands of the double helix of DNA, preventing DNA replication and RNA transcription. Chloroquine can also inhibit the incorporation of phosphate into the DNA and RNA of malarial parasites, and interfere with the reproduction of malarial parasites due to the reduction of nucleic acid synthesis. In addition, chloroquine can increase the pH in the food vacuole and lysosome of malarial parasites, affecting the digestion of hemoglobin, leading to amino acid deficiency and causing the disintegration of ribonucleic acid. Chloroquine can also interfere with the entry of fatty acids into phospholipids, control glutamate dehydrogenase and hexokinase, etc. Its early effect may be to cause the aggregation of hemochromatin (ferroprotoporphyrin IX) and form a toxic chloroquine-hemochromatin complex to exert its antimalarial effect.

This product is a benzimidazole derivative, which is rapidly metabolized into sulfoxide, sulfone alcohol and 2-amine sulfone alcohol in the body. It selectively and irreversibly inhibits the polymerization of the cytoplasmic microtubule system of the parasite's intestinal wall cells, blocks its absorption of various nutrients and glucose, leads to the depletion of endogenous glycogen in the worm, and inhibits the fumarate reductase system, preventing the production of adenosine triphosphate, making it impossible for the worm to survive and reproduce. Similar to mebendazole, this product can also cause the degeneration of the cytoplasmic microtubules of the worm's intestinal cells, and bind to its microtubule protein, causing intracellular transport blockage, resulting in the accumulation of Golgi endocrine granules, the gradual dissolution of the cytoplasm, and the complete degeneration of the absorbing cells, causing the death of the worm. This product has the effect of completely killing hookworm eggs and whipworm eggs and partially killing ascarid eggs. In addition to killing and expelling various nematodes parasitic in animals, it also has a significant killing and expelling effect on tapeworms and cysticerci.

Sulfonamide antibiotics, when used in combination with trimethoprim, can double block bacterial folate metabolism and have good antibacterial effects against a variety of bacteria.

It inhibits dihydrofolate reductase and can be used together with sulfamethoxazole to enhance the synergistic antibacterial effect and reduce drug-resistant strains.

It can inhibit the synthesis of prostaglandins and has antipyretic and analgesic effects

It is a central nervous system stimulant that can enhance the antipyretic and analgesic effects of acetaminophen and reduce central nervous system inhibitory effects such as drowsiness and dizziness caused by other drugs.

It is an antihistamine that can relieve runny nose, nasal congestion, and sneezing symptoms.

It has antipyretic and sedative effects

The saturation of cholesterol in bile is reduced by inhibiting the reabsorption of cholesterol in the intestine and reducing the secretion of cholesterol into the bile; cholesterol stones may be gradually dissolved due to the dispersion of cholesterol and the formation of liquid crystals; the treatment is completed by relatively replacing lipophilic, detergent-like toxic bile acids and promoting the secretion of hepatocytes and immune regulation.