Antiparasitic Drugs

Praziquantel is a kind of anthelmintic for human and animals, which is specially used to treat tapeworms and trematodes. It is especially effective for Schistosoma japonicum, Clonorchis sinensis and Taenia cantonensis. Praziquantel is one of the most important drugs for basic public health in the world.

Pyrimethamine is a broad-spectrum veterinary drug widely used for antigen insects. In addition, pyrimethamine is also used in aquaculture, which can enhance the disease resistance of aquatic fish. However, the side effects of pyrimethamine are serious, excessive use can damage the reproductive system of livestock and poultry, and is not easy to recover. Pyrimethamine can inhibit the primary infrared phase of some falciparum malaria and vivax malaria, so it is a better preventive drug. Although it has no obvious effect on the gametophyte of Plasmodium, the development of Gametophyte in mosquitoes can be affected after the blood containing the drug enters the mosquitoes, so the transmission can be blocked. The principle of action is to inhibit dihydrofolate reductase, affect the utilization of tetrahydrofolate, reduce the synthesis of nucleic acid and inhibit the reproduction of Plasmodium. At the same time, pyrimidine and chloroquine can protect the placental pathological changes after malaria infection by reducing the levels of oxidative stress and apoptosis, and can also effectively reduce the proportion of infected red blood cells in the blood, so as to achieve a good effect of malaria treatment. Moreover, it has enrichment effect in aquatic products, beyond a certain range, it will cause hemolytic anemia after human consumption, and even has direct toxicity to the central nervous system.

This product belongs to 8-aminoquinoline derivatives. It has strong killing effect on the infrared phase and gametophyte of Plasmodium. It is an effective drug to prevent recurrence and interrupt transmission. The antimalarial mechanism may be the interference of DNA synthesis of Plasmodium. Plasmodium must provide some enzymes or coenzymes for pentose phosphate pathway metabolism in the infrared phase by human liver cells. Due to the hydroxylation of primaquine, a large number of hydrogen donors from liver cells are consumed, resulting in the lack of enzymes or coenzymes used by Plasmodium, resulting in the death of Plasmodium in the infrared phase. This product can kill Plasmodium vivax, Plasmodium vivax, Plasmodium falciparum and Plasmodium ovale in the infrared phase schizonts. The best effect is to kill Plasmodium vivax. It can also kill gametophytes of various Plasmodium species. It has the strongest effect on Plasmodium falciparum, but has very weak effect on erythrocytic schizonts.

Artesunate is an artemisinin derivative that is the hemisuccinate ester of the lactol resulting from the reduction of the lactone carbonyl group of artemisinin. It is used, generally as the sodium salt, for the treatment of malaria. It has a role as an antimalarial. It is an artemisinin derivative, a sesquiterpenoid, a dicarboxylic acid monoester, a cyclic acetal, a semisynthetic derivative and a hemisuccinate.

Sulfachlorpyrazine sodium is a special sulfa drug for coccidiosis, which is widely used in livestock and poultry coccidiosis. This product can compete for dihydrofolate synthase and affect the synthesis of dihydrofolate, thus inhibiting the growth and reproduction of bacteria and coccidia. The effect of this product on coccidiosis of poultry is similar to that of Sulfaquinoxaline, but it has stronger antibacterial effect, and can even treat fowl cholera and chicken typhoid, so it is most suitable for the treatment of coccidiosis outbreak.