• Estradiol is a synthetic estrogen that may be used to treat symptoms associated with menopause or other conditions that cause low estrogen levels.
• Estradiol is the main type of estrogen that circulates naturally in humans. In women with menstrual periods, 70 to 500mcg of natural estradiol is secreted daily, depending on the phase of the menstrual cycle. After menopause, the adrenal cortex secretes a precursor to estrogen called androstenedione, which is converted by peripheral tissues into estrone, which is the most abundant circulating estrogen in postmenopausal women.
• Estradiol also plays a critical role in male sexual function being essential for modulating libido, erectile function, and spermatogenesis.
• All estrogens act by binding to estrogen receptors in estrogen-responsive tissues. Estrogens work by a negative feedback mechanism to reduce circulating levels of gonadotrophins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in postmenopausal women.
• Estradiol belongs to the class of medicines called estrogens.

• May be used for the treatment of moderate to severe vasomotor symptoms (eg, hot flashes/flushes), and vulvar and vaginal atrophy associated with menopause. However, topical estrogen products are preferred if just prescribing for vulvar and vaginal atrophy.
• Treats low estrogen levels associated with hypogonadism, castration, or primary ovarian failure.
• May be used in appropriate patients for the palliative care of breast cancer in women or men with metastatic disease.
• May be used in the palliation of advanced androgen-dependent prostate cancer.
• May be considered for the prevention of postmenopausal osteoporosis in women at significant risk and for whom non-estrogen treatments are not appropriate. However, the 2017 American College of Physicians (ACP) guidelines do not recommend its use for this indication.
• Generic estradiol is available.

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

• Bleeding changes, an increase in the incidence of vaginal candidiasis, breast pain and discharge, high blood pressure, nausea, vomiting, abdominal cramps, scalp hair loss, hirsutism, headache, mood disturbances, weight changes, fluid retention, skin changes, or an exacerbation of endometriosis. Estradiol may also exacerbate pre-existing conditions such as asthma, diabetes, epilepsy, and migraine and interfere with some laboratory tests.
• Estrogens are associated with an increased risk of endometrial cancer. All women taking estradiol should be monitored and any persistent or recurrent abnormal vaginal bleeding should be investigated, and endometrial sampling undertaken when indicated.
• An increased risk of heart attack (myocardial infarction), stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis have been associated with estrogen use (including estradiol), with or without progestins. An increased risk of dementia has also been reported in postmenopausal women 65 years of age or older.
• Estrogens, with or without progestins should be prescribed at the lowest effective dose for the shortest possible time.
• With regards to osteoporosis, estradiol has been shown to prevent vertebral bone loss in postmenopausal women. However, it does not restore bone mass to premenopausal levels, and once discontinued, bone loss reverts to what it was during the immediate postmenopausal period. The 2017 ACP guidelines for the treatment of osteoporosis do not recommend estrogen therapy for postmenopausal women with established osteoporosis.
• Should not be used in women with undiagnosed abnormal genital bleeding, with a known or suspected history of breast cancer except in appropriate patients when used for palliation, with estrogen-dependent cancer, with active deep vein thrombosis, pulmonary embolism, or a history of these conditions. Estradiol is also not suitable for people with a recent history of stroke or a heart attack or other thromboembolic disease, liver disease, or known or suspected pregnancy.
• Estrogen use is associated with a two to four-fold increased risk in gallbladder disease requiring surgery. It may also lead to severe high calcium levels in patients with breast cancer or bone metastases. Visual abnormalities have also been reported.
• In women who have not had a hysterectomy, the addition of progestin for 10 days each cycle lowers the risk of endometrial hyperplasia (may be a precursor to endometrial cancer).
• Blood pressure and cholesterol/triglyceride levels should be monitored regularly throughout estrogen therapy.
• People with hypothyroidism receiving replacement therapy may require increased doses of thyroid replacement therapy when taking estrogens.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

• Take estradiol exactly as directed by your doctor. The dosage varies depending on what you are taking estradiol for. Do not increase or decrease the dose unless instructed to do so. You should only take estradiol for short periods when used to treat menopausal symptoms. Talk to your doctor about this
• Your doctor may add a progestin to your estradiol therapy. This is to reduce the risk of changes to your endometrium.
• Report any unusual vaginal bleeding, heart pain, breast lumps, dizziness, severe headaches, shortness of breath, changes in vision, leg pains, or changes in your speech or skin to your doctor immediately.
• There is an increased risk of cancer associated with estradiol use. Discuss this with your doctor.
• Keep your scheduled appointments with your doctor. You should go for a checkup at least once a year. Ensure you go for your recommended screenings (eg, mammograms).
• If you smoke, have high blood pressure, diabetes, are overweight, or have high cholesterol your risk of heart disease associated with estradiol use is increased.
• Keep estradiol tablets out of reach of children. Do not share your tablets with anybody else.

• Estradiol is substantially more potent than its metabolites, estrone, and estriol at the estrogen receptor level.
• Estradiol is commonly synthesized as a prodrug ester (for example, estradiol acetate, estradiol valerate) to improve its bioavailability. Ethinylestradiol is a synthetic form of estradiol that is commonly used in oral contraceptives because it is absorbed better and is not so easily metabolized.

Medicines that interact with estradiol may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with estradiol. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with estradiol include:

• anastrozole
• anticoagulants, such as warfarin
• ascorbic acid
• clozapine
• corticosteroids, such as prednisone
• dantrolene
• hyaluronidase
• lamotrigine
• medications for diabetes, including insulin
• medications that induce or inhibit cytochrome p450 enzymes, CYP3A4
• NSAIDs, such as diclofenac, ibuprofen, or naproxen
• oral contraceptives
• somatropin
• theophylline
• thyroid products.

Note that this list is not all-inclusive and includes only common medications that may interact with estradiol. You should refer to the prescribing information for estradiol for a complete list of interactions.