Trimethoprim (TMP) is an antibacterial agent, a lipophilic weak base, and its chemical structure belongs to the pyrimethamine class. It has antibacterial activity against Escherichia coli, Klebsiella, Proteus mirabilis, Salmonella, and Shigella, but has no obvious antibacterial effect on Streptococcus pneumoniae, Neisseria gonorrhoeae, and Neisseria meningitidis, and has no effect on Pseudomonas aeruginosa. The mechanism of action of this product is to interfere with bacterial folic acid metabolism. It mainly selectively inhibits the activity of bacterial dihydrofolate reductase, so that dihydrofolate cannot be reduced to tetrahydrofolate, and synthetic folic acid is the main component of nucleic acid biosynthesis. Therefore, this product prevents the synthesis of bacterial nucleic acids and proteins, and the binding of this product to bacterial dihydrofolate reductase is 50,000 to 60,000 times tighter than that to mammalian enzymes. The combination of this product and sulfonamides can double block the bacterial folic acid synthesis metabolism, have a synergistic effect, enhance the antibacterial activity of sulfonamides, and convert the antibacterial effect into a bactericidal effect, reducing the production of drug-resistant strains.

By inhibiting the synthesis of prostaglandins and other effects, it can eliminate and reduce the activity of pain-causing factors in a multi-target and all-round manner, quickly relieving headaches and neuralgia; it can achieve an antipyretic effect by regulating the hypothalamic temperature regulation center; and it can synergize with caffeine to enhance the analgesic effect.

Enhance the analgesic effect, strengthen the excitation process of the cerebral cortex, invigorate the spirit, and improve symptoms such as fatigue, discomfort and lack of energy caused by headaches and neuralgia.

As a neurotrophic drug, it improves the activity of nerve tissue, enhances nerve nutrition, promotes the metabolism of nerve tissue, and restores its normal physiological function; it has a therapeutic effect on neurasthenia and memory loss.