title: An evaluation of the drug interaction potential of pazopanib, an oral vascular endothelial growth factor receptor tyrosine kinase inhibitor, using a modified Cooperstown 5+1 cocktail in patients with advanced solid tumors.
abstract: Pazopanib, an oral inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-kit kinases, inhibits multiple cytochrome P450 (CYP450) enzymes in vitro. This study in patients with advanced cancer evaluated the effect of pazopanib on CYP450 function by comparing the pharmacokinetics of CYP-specific probe drugs in the presence and absence of pazopanib. The probes used included midazolam (CYP3A specific), warfarin (CYP2C9 specific), omeprazole (CYP2C19 specific), caffeine (CYP1A2 specific), and dextromethorphan (CYP2D6 specific). The estimated ratios of the geometric means (90% confidence interval (CI)) for the area under the curve to the last measurable point (AUC(0-t)) for these probe drugs with/without pazopanib were as follows: midazolam, 1.35 (1.18-1.54); omeprazole, 0.81 (0.59-1.12); caffeine, 1.00 (0.77-1.30); and S-warfarin, 0.93 (0.84-1.03). The geometric least-squares (LS) mean ratio of urine dextromethorphan:dextrorphan ranged from 1.33 (0-4-h interval) to 1.64 (4-8-h interval). The data suggest that pazopanib is a weak inhibitor of CYP3A4 and CYP2D6 and has no effect on CYP1A2, CYP2C9, and CYP2C19 in patients with advanced cancer.
authors.affiliation: Section of Clinical Pharmacology, Department of Hematology-Oncology, National University Hospital, Singapore, Singapore.
authors.forename: B C
authors.initials: BC
authors.lastname: Goh
authors.forename: N J
authors.initials: NJ
authors.lastname: Reddy
authors.forename: U B
authors.initials: UB
authors.lastname: Dandamudi
authors.forename: K H
authors.initials: KH
authors.lastname: Laubscher
authors.forename: T
authors.initials: T
authors.lastname: Peckham
authors.forename: J P
authors.initials: JP
authors.lastname: Hodge
authors.forename: A B
authors.initials: AB
authors.lastname: Suttle
authors.forename: T
authors.initials: T
authors.lastname: Arumugham
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: C-F
authors.initials: CF
authors.lastname: Xu
authors.forename: J
authors.initials: J
authors.lastname: Lager
authors.forename: M M
authors.initials: MM
authors.lastname: Dar
authors.forename: L D
authors.initials: LD
authors.lastname: Lewis
mesh_terms: D000284:Administration, Oral; D000368:Aged; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D005838:Genotype; D006801:Humans; D007191:Indazoles; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D015335:Molecular Probes; D009369:Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D009513:New Hampshire; D010641:Phenotype; D011110:Polymorphism, Genetic; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D011743:Pyrimidines / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012846:Singapore; D013379:Substrate Specificity; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D065607:Cytochrome P-450 Enzyme Inhibitors; D007191:Indazoles; D007527:Isoenzymes; D015335:Molecular Probes; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D013449:Sulfonamides; C516667:pazopanib; D003577:Cytochrome P-450 Enzyme System; D040262:Receptors, Vascular Endothelial Growth Factor