Страна: Южна Африка
Език: английски
Източник: South African Health Products Regulatory Authority (SAHPRA)
Schering
MIRANOVA SCHEDULING STATUS: S3 PROPRIETARY NAME (and dosage form): MIRANOVA Tablets COMPOSITION The 28-day pack (Every-Day pack) contains 21 hormonal tablets each with levonorgestrel 0,1 mg and ethinylestradiol 0,02 mg plus 7 inactive tablets. PHARMACOLOGICAL CLASSIFICATION A. 21.8.2 Progesterones with estrogens. PHARMACOLOGICAL ACTION Pharmacodynamics The contraceptive effect of Miranova is based on the inhibition of ovulation and the changes in the cervical secretion. Pharmacokinetics • Levonorgestrel Absorption Orally administered levonorgestrel is completely absorbed. Peak serum concentrations of 2,3 ng/mL are reached at about 1,3 hours after single ingestion. Levonorgestrel is almost completely bioavailable after oral administration. Distribution Levonorgestrel is bound to serum albumin and to sex hormone binding globulin (SHBG). Only 1,1% of the total serum drug concentrations are present as free steroid, approximately 65% are specifically bound to SHBG and about 34% are non-specifically bound to albumin. The ethinylestradiol-induced increase in SHBG influences the proportion of levonorgestrel bound to the serum proteins, causing an increase of the SHBG-bound fraction and a decrease of the albumin-bound fraction. The apparent volume of distribution of levonorgestrel is 129 L. Metabolism Levonorgestrel is completely metabolised by the known pathways of steroid metabolism. The clearance rate from serum is approximately 1,0 mL/min/kg. Elimination Levonorgestrel serum levels decrease in two phases. The terminal disposition phase is characterised by a half-life of approximately 25 hours. Levonorgestrel is not excreted in unchanged form. Its metabolites are excreted at a urinary to biliary ration of about 1:1. The half-life of metabolite excretion is about 1 day. Steady-state condi Прочетете целия документ