CINV is primarily caused by the cytotoxic effects of chemotherapy drugs on the body. These drugs target rapidly dividing cancer cells, but they also affect normal cells in the gastrointestinal tract and the central nervous system, particularly the chemoreceptor trigger zone (CTZ) and the vomiting center in the brain. This leads to the release of neurotransmitters like serotonin, dopamine, and substance P, which activate nausea and vomiting pathways.
