Morphine modulates doxorubicin uptake and improves efficacy of chemotherapy in an intracranial xenograft model of human glioblastoma.

Morphine may alter the permeability of Blood-Brain Barrier (BBB), enhancing the access of molecules normally unable to cross it, as Doxorubicin (Dox). In addition, morphine seems to mediate the uptake of Dox into the brain by its reduced efflux mediated by P-glycoprotein (P-gp). We evaluated the antitumor efficacy of Dox plus morphine treatment by an orthotopic glioblastoma xenograft model.