What Is Capecitabine Used For?
How Does Capecitabine Work?Capecitabine is a unique chemotherapy medication. In the body, it is transformed into 5-FU (fluorouracil). Fluorouracil is a chemotherapy medication that is given intravenously (by IV). Fluorouracil cannot be given by mouth because it does not absorb well from the digestive tract into the body. Capecitabine was developed as a way for fluorouracil to be given orally. When capecitabine is taken by mouth, it is easily absorbed into the body. The body then transforms capecitabine to fluorouracil, providing all the benefits of fluorouracil without the need of an IV.
Fluorouracil works in at least two different ways. Fluorouracil interferes with a cell's ability to make new DNA (molecules that contain the cell's genetic information). In order to multiply, cells need to make new DNA. By interfering with DNA production, fluorouracil stops cells from multiplying. Enzymes in cells also mistakenly use fluorouracil when building important parts of the cell that are responsible for making proteins (which causes these parts to stop functioning).
Together, these two actions can cause permanent damage to cells, including healthy noncancerous cells. However, cancer cells divide more rapidly, producing more DNA and proteins, and are therefore more affected by capecitabine. Also, cancer cells often have higher levels of the enzyme that transforms capecitabine into fluorouracil, which helps capecitabine to have a greater effect in cancer cells compared to normal cells.