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Absolute bioavailability of letrozole in healthy postmenopausal women
Author(s) -
Sioufi A.,
Gauducheau N.,
Pineau V.,
Marfil F.,
Jaouen A.,
Cardot J. M.,
Godbillon J.,
Czendlik C.,
Howald H.,
Pfister CH.,
Vreeland F.
Publication year - 1997
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/(sici)1099-081x(199712)18:9<779::aid-bdd64>3.0.co;2-5
Subject(s) - letrozole , bioavailability , pharmacokinetics , volume of distribution , pharmacology , metabolite , glucuronide , aromatase inhibitor , chemistry , urine , medicine , breast cancer , active metabolite , aromatase , cancer
Letrozole is a new non‐steroidal inhibitor of the aromatase enzyme system. It is currently under development for the treatment of postmenopausal women with advanced breast cancer. Absolute bioavailability of letrozole when given orally as one 2·5 mg film‐coated tablet in comparison to the same dose given intravenously as a bolus injection was studied in 12 healthy postmenopausal women. Letrozole absolute systemic bioavailability after p.o. administration was 99·9±16·3%. Elimination of letrozole was slow. Total‐body clearance of letrozole from plasma after i.v. administration was low (2.21 L h −1 ). The calculated distribution volume at steady state (1.87 L kg −1 ) suggests a rather high tissue distribution. Biotransformation of letrozole is the main elimination mechanism with the glucuronide conjugate of the secondary alcohol metabolite being the predominant species found in urine. The two study treatments were tolerated equally well. © 1997 John Wiley & Sons, Ltd.