Letrozol Teva Filmtabletten 2.5mg 100 Stück

Description

Pharmacokinetics

• Absorption

Letrozole is rapidly and completely absorbed from the gastrointestinal (GI) tract, with an average bioavailability of 99.9%. Food intake slightly reduces the rate of absorption. The mean value of time to reach the maximum concentration of letrozole in plasma (Tmah) is 1 hour when taking letrozole on an empty stomach and 2 hours – when taking with food; the mean value of maximum concentration (Cmah) is 129±20.3 nmol/l when taking on an empty stomach and 98.7±18.6 nmol/l – when taking with food, but the degree of absorption of letrozole (when assessed by the area under the curve “concentration-time” (AUC)) does not change. Small changes in the absorption rate are considered to be of no clinical significance, therefore letrozole can be taken independently of food intake.

• Distribution

The binding of letrozole to blood plasma proteins is approximately 60% (mainly to albumin – 55%). The concentration of letrozole in erythrocytes is approximately 80% of that in plasma. After administration of 2.5 mg of radioactively labelled letrozole, approximately 82% of the radioactivity in plasma was unchanged, thus systemic exposure of metabolites is extremely low.

Letrozole is rapidly and largely distributed in tissues. The apparent volume of distribution at equilibrium is about 1.87±0.47 l/kg.