Final answer:
Chemotherapy drugs cause emesis by stimulating the chemoreceptor trigger zone (CTZ) in the brain. They target rapidly dividing cells to combat cancer, but this also leads to side effects on normal cells with high turnover rates. Targeted therapies seek to address these normal cells' adverse effects.
Step-by-step explanation:
Cancer chemotherapy drugs cause emesis, primarily by stimulating the chemoreceptor trigger zone (CTZ). The CTZ is located in the brain, and when activated, it can induce the vomiting reflex. Chemotherapy drugs interfere with cell division which is vital for cancer cells' growth and spread, but they also affect normal cells that divide rapidly, leading to side effects such as nausea, hair loss, and damage to the gastrointestinal lining. Although these normal cells typically repair themselves after chemotherapy, the immediate side effects can be distressing for patients.
Utilizing combination chemotherapy, where two or more drugs are given simultaneously, is often more effective than single-drug therapy. However, because the drugs are not cancer-specific, they also harm healthy tissue. Sophisticated targeted therapies aim to reduce these adverse effects by focusing on specific molecular differences between cancerous and normal cells.