In the study, scientists discovered that activating the β - isoform of the platelet-derived growth factor receptor (PDGFR) caused morphine tolerance in animals not previously exposed to morphine.
Imatinib is commonly used to treat certain types of leukemia and gastrointestinal tumors. It targets a number of cellular receptors, including the PDGFR, which is heavily expressed in those cancer cells.
In this study, imatinib prevented morphine tolerance, and importantly, completely reversed tolerance in rats that received high morphine doses continuously for several days, which reflects how morphine and other opioids are often given to chronic pain patients.