Pharmacokinetics of Etonogestrel and Ethinylestradiol Released from a Combined Contraceptive Vaginal Ring

Authors: Timmer C.J.¹; Mulders T.M.T.²

Source: Clinical Pharmacokinetics, Volume 39, Number 3, September 2000 , pp. 233-242(10)

Publisher: Adis International

Abstract:

Objective: To assess the pharmacokinetics of etonogestrel and ethinylestradiol released from a novel combined contraceptive vaginal ring (NuvaRing) releasing etonogestrel 120µg and ethinylestradiol 15µg per day and compare them with those of a combined oral contraceptive containing desogestrel 150µg/ethinylestradiol 30µg (DSG/EE COC).

Design and setting: This was a nonblind, randomised, crossover study in 16 healthy women.

Methods: All volunteers received one cycle of DSG/EE COC before being randomised to 1 of 2 treatment groups. The participants in group 1 received 1 cycle of DSG/EE COC, a treatment period with NuvaRing and an intravenous bolus injection of etonogestrel/ethinylestradiol (150µg/30µg). Those in group 2 received a NuvaRing treatment period, 1 cycle of DSG/EE COC and the same intravenous bolus injection.

Results and conclusions: After the insertion of NuvaRing, maximum serum concentrations of etonogestrel and ethinylestradiol were achieved in approximately 1 week. The concentrations subsequently showed a gradual linear decrease in time. The maximum serum concentrations of etonogestrel and ethinylestradiol were approximately 40 and 30%, respectively, of those for the DSG/EE COC. In comparison with the DSG/EE COC, the absolute bioavailability for NuvaRing was higher for etonogestrel (102.9 vs 79.2%) and similar for ethinylestradiol (55.6 vs 53.8%). Taking the difference in daily doses into account, systemic exposure to etonogestrel was similar for NuvaRing and the DSG/EE COC, whereas systemic exposure to ethinylestradiol with NuvaRing was only approximately 50% of that for the DSG/EE COC.

Keywords: Contraceptives, pharmacokinetics; Ethinylestradiol/desogestrel, pharmacokinetics

Language: English

Document Type: Original article

Affiliations: 1: Department of Drug Metabolism and Kinetics, N.V. Organon, Oss, The Netherlands 2: Clinical Development Department, N.V. Organon, Oss, The Netherlands *

Publication date: 2000-09-01

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• In this Subject: Pharmacology
• By this author: Timmer C.J. ;  Mulders T.M.T.

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