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NCI Drug Dictionary


carbon C 11 N-desmethyl-loperamide 
A radiopharmaceutical containing N-desmethyl loperamide (dLop) labeled with carbon 11 (11C), used to measure the activity of efflux transporter P-glycoprotein (P-gp) in positron emission tomography (PET). Upon administration, carbon C 11 N-desmethyl-loperamide acts as a substrate for the efflux transporter P-gp. Upon uptake by P-gp at the blood-brain barrier (BBB) and subsequent PET imaging, this radioligand may allow for prediction of P-gp function and expression in brain tumor patients. As P-gp activity may influence response to therapy, measuring P-gp activity may be beneficial when choosing chemotherapy. P-gp, encoded by the MDR-1 gene and a member of the ATP-binding cassette (ABC) superfamily of transmembrane transporters, is overexpressed by some MDR tumors and may contribute to multidrug resistance to chemotherapy. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus)
Synonym:carbon C 11 loperamide hydrochloride
Chemical structure:(11C)N-desmethyl-loperamide