abstract: Pharmacokinetics and antitumor activity of patupilone combined with midazolam or omeprazole in patients with advanced cancer (inhibitors)

PURPOSE:
Patupilone is a novel microtubule-targeting cytotoxic agent with potential interaction with CYP3A4/CYP2C19 enzymes. Midazolam and omeprazole are primarily metabolized by CYP3A4 and CYP2C19, respectively. We evaluated the inhibitory effects of patupilone on the CYP3A4/CYP2C19 pathways.

METHODS:
This study had 2 parts: in an initial core phase, patients were randomly assigned to receive midazolam 4 mg or omeprazole 40 mg PO (days 1 and 29) and patupilone 10 mg/m(2) IV (days 8 and 29). Patients without progression continued patupilone every 3 weeks until disease progression or unacceptable toxicity (extension phase).

Abstract/free full text - Associations between tamoxifen, estrogens, and FSH serum levels during steady state tamoxifen treatment of postmenopausal women with breast cancer

"Conclusions

We have shown an association between tamoxifen and its metabolites and estrogen serum levels. An impact of CYP2C19 predicted activity on tamoxifen, as well as estrogen kinetics may partly explain the observed association between tamoxifen and its metabolites and estrogen serum levels. Since the role of estrogen levels during tamoxifen therapy is still a matter of debate further prospective studies to examine the effect of tamoxifen and estrogen kinetics on treatment outcome are warranted."