Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

In vitro tamoxifen reverses multidrug resistance (MDR). To evaluate the clinical potential of using tamoxifen in this way, intermittent high-dose tamoxifen was combined with oral etoposide in 86 patients. At 320 mg/day tamoxifen for 6 days, mean plasma levels of tamoxifen in 11 patients increased from 453 ng/ml (range 269-664) on day 2 to 984 ng/ml (578-1336) on day 6. Of 31 patients who had plasma tamoxifen measured during the time of etoposide administration (days 4-6), 13(43%) were over 1111 ng/ml (3 mumol/l), an active in vitro level. Potentially active levels of the principal metabolite, N-desmethyl tamoxifen, were also obtained but accumulation was slower. Emesis and thromboembolism were toxicities. Tamoxifen is a modifier of MDR, a role that warrants further clinical studies.

Original publication

DOI

10.1016/0959-8049(92)90119-m

Type

Journal article

Journal

Eur J Cancer

Publication Date

1992

Volume

28A

Pages

805 - 810

Keywords

Administration, Oral, Animals, Antineoplastic Combined Chemotherapy Protocols, Cricetinae, Dose-Response Relationship, Drug, Drug Administration Schedule, Drug Resistance, Drug Synergism, Etoposide, Female, Humans, Male, Neoplasms, Tamoxifen