The hydroxyl group at the 4 position changes from cis to trans. It is a non-specific drug for the cell cycle, and its main site of action is the cell nucleus. The mechanism of action of this product is related to its ability to bind to DNA. When this product is added to cells cultured in vitro, it can quickly penetrate into the cell, enter the cell nucleus and bind to DNA, thereby inhibiting nucleic acid synthesis and mitosis. It has been confirmed that epirubicin has a broad spectrum of anti-experimental tumor effects and also has an inhibitory effect on topoisomerase. The therapeutic effect is equal to or slightly higher than that of doxorubicin, while the toxicity, especially the cardiac toxicity, is lower than that of doxorubicin.

This product is the main isomer of doxorubicin, which is the trans configuration of the C4 hydroxyl group in the amino sugar part of doxorubicin. It can be directly embedded in DNA, form a complex with the double helix structure of DNA, block the formation of RNA dependent on DNA, and has the kinetic energy to form superoxide free radicals. The site of action of this product is on the C4 hydroxyl group of the amino sugar part (its excretion can reach 1/3 of the total excretion). This was only found after using this drug, but not when using daunorubicin and doxorubicin. This may be the main reason why epirubicin is cleared faster in the body and its toxicity is lower than that of doxorubicin at the same dose.

The drug can penetrate into cells, bind to chromosomes, interfere with DNA and RNA synthesis, cleave DNA through topoisomerase II to destroy its structure, produce cytotoxic compounds related to oxidation/reduction, and affect cell membrane function. Doxorubicin is active throughout the cell cycle and is particularly sensitive to rapidly proliferating tissues such as tumor tissues.

This drug is an anthracycline antibiotic with antimitotic and cytotoxic effects. Its mechanism of action is to act on topoisomerase II and inhibit nucleic acid synthesis. The change in the 4-position of the anthracene ring structure makes the compound lipophilic, which increases the cell's uptake of the drug.

It has anti-mitotic and cytotoxic effects. Its mechanism of action is to act on topoisomerase II and inhibit nucleic acid synthesis. The change in the 4-position of the anthracene ring structure makes the compound lipophilic and increases the cell's uptake of the drug.