An investigation of the pharmacokinetics of ethynylestradiol in women using radioimmunoassay

D J BackM J Watts


A radioimmunoassay for ethynylestradiol (EE) which is applicable to plasma samples obtained from women, who have taken a combination type oral contraceptive, has been developed and fully validated. Plasma concentration of EE rise to a peak of 128 pg/ml following the oral administration of 50 microgram EE. Following the intravenous administration of the same dose of EE, plasma concentrations of the steroid declined biexponentially, the two half-lives being 0.83 and 6.75 hours. Comparison of the results of the intravenous and oral administration of the steroid suggested that its oral bioavailability is 42%. Although EE thus has a lower bioavailability than norethindrone, the pharmacokinetics of the two steroids, as reflected by half-lives, plasma clearance and volume of distribution, are very similar. The occurrence of a secondary peak in plasma at around 12 hours after dosing gave strong evidence that EE undergoes enterohepatic circulation in women; an event that may have considerable clinical significance.


Mar 1, 1977·Journal of Reproduction and Fertility·J R PasqualiniF A Kincl
Sep 1, 1976·Contraception·K Fotherby, R J Warren

❮ Previous
Next ❯


Dec 1, 1991·Advances in Contraception : the Official Journal of the Society for the Advancement of Contraception·M Orme, D J Back
Jan 1, 1996·Contraception·A WeberA Balogh
Apr 1, 1981·Journal of Steroid Biochemistry·D J BackP H Rowe
May 1, 1981·Journal of Steroid Biochemistry·K FotherbyH Breuer
Mar 1, 1982·Journal of Steroid Biochemistry·D J BackE Thomas
Apr 1, 1983·Journal of Steroid Biochemistry·S M SimH J Eyssen
Jan 1, 1984·Journal of Steroid Biochemistry·H AdlercreutzJ T Korpela
Sep 1, 1988·Journal of Steroid Biochemistry·G M Pacifici, D J Back
Jan 1, 1989·Pharmacology & Therapeutics·M L OrmeS Ball
Sep 8, 1993·Journal of Chromatography·N FernándezM Sierra
Jun 1, 1991·The Journal of Steroid Biochemistry and Molecular Biology·K Fotherby
Apr 17, 2007·Contraception·Fang KejuanPeter Fajans
Sep 29, 1984·Lancet·M OrmeD H Jones
Dec 1, 1990·British Journal of Clinical Pharmacology·P CrawfordM Orme
Nov 1, 1992·Epilepsia·P Klosterskov JensenG P Menge
Jul 12, 1980·British Medical Journal
May 9, 1981·British Medical Journal·D J BackP H Rowe
Dec 5, 1981·British Medical Journal·M H Briggs
Jul 10, 2002·Clinical Pharmacokinetics·James W McAuley, Gail D Anderson
Jan 27, 2007·Clinical Pharmacokinetics·Hongjian ZhangA David Rodrigues
May 1, 1989·American Journal of Obstetrics and Gynecology·J W Goldzieher
Dec 1, 1990·American Journal of Obstetrics and Gynecology·M L Orme, D J Back
Dec 1, 1990·American Journal of Obstetrics and Gynecology·J P Hanker
May 1, 1986·Oral Surgery, Oral Medicine, and Oral Pathology·R Bainton

❮ Previous
Next ❯

Related Concepts

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.


Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.


Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.