General
Description & Use
Ethinyl estradiol (also known in generic form as Lynoral,
Generic Estrace, Femtrace, Gynodiol) is a pure synthetic estradiol.
A female hormone and HRT used to reduce menopause symptoms (e.g.,
hot flushes), for brittle bones (osteoporosis), and treats certain
cancers in both men and women. Also very popular for M2F transsexuals
in gender reassignment
and the usual hormone initially supplied to M2F transexuals by
gender reassignment clinics when undertaking hormone therapy.
Ethinylestradiol,
also ethinyl estradiol is a derivative of estradiol. Ethinyl estradiol
is an orally bio-active estrogen used in almost all modern formulations
of combined oral contraceptive pills (the Pill). It is one of
the most commonly used medications. The first orally active synthetic
steroidal estrogen, ethinylestradiol (17a-ethynylestradiol), the
17a-ethynyl analog of estradiol, was synthesized in 1938 by Hans
Herloff Inhoffen and Walter Hohlweg at Schering AG in Berlin.
Ethinylestradiol was approved by the FDA in the U.S. in 1943 and
marketed by Schering as Estinyl. The FDA withdrew approval of
Estinyl effective June 4, 2004 at the request of Schering, who
had discontinued marketing Estinyl. While estradiol is readily
absorbed when taken orally, it is also quickly inactivated by
the liver.
Also
see Estrofem® Estradiol
and Progynova
(non synthetic and plant extracted estradiol)
Substitution
at C17 of the estrane steroid with an ethinyl group proved to
provide an estrogen that is much more resistant to degradation
and paved the way for the development of oral contraceptives.
Ethinyl estradiol is absorbed in the small intestine and reaches
a serum peak about 2 hours later. It undergoes extensive metabolism
in the liver involving the cytochrome P450 3A4 isoenzyme. Ethinyl
estradiol and its metabolites are in excreted with the bile. Due
to the effect of enterohepatic circulation a second peak is seen
several hours later.
Individually,
wide variations exist in the overall absorption process, and can
be further modified by drugs (i.e. antibiotics) that affect the
enterohepatic circulation or liver enzymes. In circulation EE
is almost fully bound to plasma albumin. It is metabolized by
hydroxylation of the aromatic ring and excreted in both, feces
and urine, in part as glucuronide and sulfate conjugate. Ethinyl
estradiol is hormonally effective by activating the estrogen receptor
and thus is an estrogen. It finds its most common use in the estrogen-progestin
combination preparations of oral contraceptives. Over time, formulations
have decreased the Ethinyl estradiol dose from as high as 100
µg to as low as 20 µg. The same contraindications and precautions
apply for Ethinyl estradiol as with other estrogen medications.
Estinyl was a preparation of Ethinyl estradiol alone that was
used for the management of menopausal symptoms and female hypogonadism.[8]
Estradiol (17ß-estradiol [17 beta]) (also oestradiol) is a sex
hormone. Whilst a female hormone, it is also present in males;
it represents the major estrogen in humans. Estradiol has not
only a critical impact on reproductive and sexual functioning,
but also affects other organs including bone structure.
