Dictionary of Cancer Terms
View in Spanish: Farmacorresistencia
Drug resistance ( rih-ZIH-stunts)
The failure of cancer cells, viruses, or bacteria to respond to a drug used to kill or weaken them. The cells, viruses, or bacteria may be resistant to the drug at the beginning of treatment, or may become resistant after being exposed to the drug.
Source: National Cancer Institute Dictionary of Cancer Terms, available at www.cancer.gov/dictionary.