Estradiol acetate (EA), sold under the brand names Femtrace, Femring, and Menoring, is an

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...

medication which is used in

hormone therapy Hormone therapy or hormonal therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also be referred to as hormonal therapy or antihormone therapy. The most general classes of hormone therapy are oncologic horm ...

for the treatment of

menopausal Menopause, also known as the climacteric, is the time in women's lives when Menstruation, menstrual periods stop permanently, and they are no longer fertility, able to bear children. Menopause usually occurs between the age of 47 and 54. Medic ...

symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s in women.https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/021633s005lbl.pdf It is taken by mouth once daily or given as a

vaginal ring Vaginal rings (also known as intravaginal rings, or V-Rings) are polymeric drug delivery devices designed to provide controlled release of drugs for intravaginal administration over extended periods of time. The ring is inserted into the vagina a ...

once every three months. Side effects of estradiol acetate include breast tenderness, breast enlargement,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

, and fluid retention. Estradiol acetate is an

and hence is an

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

of the estrogen receptor, the biological target of

s like estradiol. It is an

estrogen ester An estrogen ester is an ester of an estrogen, most typically of estradiol but also of other estrogens such as estrone, estriol, and even nonsteroidal estrogens like diethylstilbestrol. Esterification renders estradiol into a prodrug of estradiol ...

and a

prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ...

of estradiol in the body. Because of this, it is considered to be a

natural Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are p ...

and bioidentical form of estrogen. Estradiol acetate was introduced for medical use in 2001. It is available in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

. The formulation for use by mouth has been discontinued in the United States.

Medical uses

Estradiol acetate is used as a component of menopausal hormone therapy to treat and prevent

s such as

hot flash Hot flashes (also known as hot flushes) are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, and ...

es and

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone ...

in women. The Women's Health Initiative studies report increased health risks for menopausal women when using unopposed estrogens. Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.

Available forms

Estradiol acetate comes in the form of 0.45, 0.9, and 1.8 mg

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or oral ...

tablet Tablet may refer to: Medicine * Tablet (pharmacy), a mixture of pharmacological substances pressed into a small cake or bar, colloquially called a "pill" Computing * Tablet computer, a mobile computer that is primarily operated by touching the s ...

s (Femtrace) and in the form of 12.4 or 24.8 mg

s that release 50 or 100 μg/day estradiol for 3 months (Femring, Menoring). However, the Femtrace product was discontinued in the

Contraindications

Contraindications of estrogens include

coagulation Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism o ...

problems,

cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, h ...

s, liver disease, and certain hormone-sensitive cancers such as

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

and

endometrial cancer Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most o ...

, among others.

Side effects

The side effects of estradiol acetate are the same as those of estradiol. Examples of such side effects include breast tenderness and enlargement,

, bloating,

edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's Tissue (biology), tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels t ...

, and melasma.

Overdose

Symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s of estrogen overdosage may include

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the Human nose, nose. Vomiting can be the result of ailments like Food-poisoning, foo ...

, bloating, increased weight, water retention, breast tenderness, vaginal discharge, heavy legs, and

leg cramps A cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the aff ...

. These side effects can be diminished by reducing the estrogen dosage.

Interactions

Inhibitor Inhibitor or inhibition may refer to: In biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...

s and

inducer In molecular biology, an inducer is a molecule that regulates gene expression. An inducer functions in two ways; namely: *By disabling repressors. The gene is expressed because an inducer binds to the repressor. The binding of the inducer to the r ...

s of

cytochrome P450 Cytochromes P450 (CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are ...

may influence the

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

of estradiol and by extension circulating estradiol levels.

Pharmacology

Pharmacodynamics

Estradiol acetate is an estradiol ester, or a

of estradiol. As such, it is an

, or an

of the estrogen receptors. Estradiol acetate is of about 15% higher

molecular weight A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

than estradiol due to the presence of its C3

acetate An acetate is a salt (chemistry), salt formed by the combination of acetic acid with a base (e.g. Alkali metal, alkaline, Alkaline earth metal, earthy, Transition metal, metallic, nonmetallic or radical Radical (chemistry), base). "Acetate" als ...

ester. Because estradiol acetate is a prodrug of estradiol, it is considered to be a

and bioidentical form of estrogen.

Pharmacokinetics

Estradiol acetate is converted into estradiol in the body.

Chemistry

Estradiol acetate is a

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic o ...

estrane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...

and the C3

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

of estradiol. It is also known as estradiol 3-acetate or as estra-1,3,5(10)-triene-3,17β-diol 3-acetate. Another common ester of estradiol in use for oral administration is estradiol valerate, which is a C17β ester of estradiol. The experimental octanol/water partition coefficient (logP) of estradiol acetate is 4.2.

History

Estradiol acetate is relatively recent to the market, having been first approved in a

formulation Formulation is a term used in various senses in various applications, both the material and the abstract or formal. Its fundamental meaning is the putting together of components in appropriate relationships or structures, according to a formul ...

as Menoring in the

in 2001, followed by a vaginal ring formulation as Femring in the

in 2002, and finally as an

preparation as Femtrace in the United States in 2004.

Society and culture

Generic names

''Estradiol acetate'' is the generic name of the drug and its .

Brand names

Estradiol acetate is marketed under the brand names Femtrace, Femring, and Menoring.

Availability

Estradiol acetate is available in the

and the

References

{{Estrogen receptor modulators Acetate esters Estradiol esters Prodrugs Secondary alcohols Synthetic estrogens