Pilot study of rosiglitazone as an in vivo probe of paclitaxel exposure

Abstract

Aims: To evaluate the use of rosiglitazone and the erythromycin breath test (ERMBT), as probes of CYP2C8 and CYP3A4, respectively, to explain inter-individual variability in paclitaxel exposure. Methods: The concentration of rosiglitazone at 3h and ERMBT results were included in a regression model to explain the variability in paclitaxel exposure in 14 subjects. Results: Rosiglitazone concentration was significantly correlated with paclitaxel exposure (P= 0.018) while ERMBT had no predictive value (P= 0.47). CONCLUSIONS The correlation between the exposure of rosiglitazone and paclitaxel likely reflects mutual dependence on the activity of CYP2C8. Rosiglitazone or similar agents may have value as in vivo probes of CYP2C8 activity. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.