Esterified estrogens Side Effects
Medically reviewed by Drugs.com. Last updated on July 28, 2020.
For the Consumer
Applies to esterified estrogens: oral tablet
- Estrogens may raise the chance of uterine cancer. Progestins may lower this chance. A warning sign for cancer of the uterus is vaginal bleeding. Report any vaginal bleeding to the doctor.
- Do not use estrogens to prevent heart disease or dementia. Using estrogens may raise the chances of having a heart attack, a stroke, breast cancer, ovarian cancer, a blood clot, or dementia.
- Use estrogens with or without progestin for the shortest time needed at the lowest useful dose.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of gallbladder problems like pain in the upper right belly area, right shoulder area, or between the shoulder blades; yellow skin or eyes; fever with chills; bloating; or very upset stomach or throwing up.
- Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
- Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
- Signs of a pancreas problem (pancreatitis) like very bad stomach pain, very bad back pain, or very bad upset stomach or throwing up.
- Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
- Dizziness or passing out.
- Change in eyesight.
- Loss of eyesight.
- Bulging eyes.
- Change in how contact lenses feel in the eyes.
- A lump in the breast, breast pain or soreness, or nipple discharge.
- Breast pain.
- Vaginal itching or discharge.
- Vaginal bleeding that is not normal.
- Low mood (depression).
- Mood changes.
- Memory problems or loss.
- Call your doctor right away if you have signs of a blood clot like chest pain or pressure; coughing up blood; shortness of breath; swelling, warmth, numbness, change of color, or pain in a leg or arm; or trouble speaking or swallowing.
What are some other side effects of this drug?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Hair loss.
- Tender breasts.
- Enlarged breasts.
- Leg cramps.
- Upset stomach or throwing up.
- Vaginal bleeding or spotting.
- Feeling nervous and excitable.
- Joint pain.
- Change in sex interest.
- Weight gain or loss.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to esterified estrogens: oral tablet
The increased risk of breast cancer due to use of estrogens is controversial. Several studies have suggested that long-term estrogen therapy may be associated with a slightly increased risk of breast cancer. Meta analysis of 51 studies (epidemiological data) supports a modest risk increase associated with long-term hormone replacement therapy (HRT).
Follow-up to the Nurses' Health Study of 1992 concluded, however, that there is an increased risk of breast cancer in women taking estrogen replacement therapy and that the risk is not reduced by concurrent use of progestins. (In that study, greater risk was associated with advanced age and prolonged duration of hormonal therapy.)
The Women's Health Initiative (WHI) which enrolled predominantly healthy postmenopausal women (n=27,000) to assess the risks and benefits of using conjugated estrogens 0.625 mg/day alone or with medroxyprogesterone acetate 2.5 mg/day compared to placebo has shown an absolute excess risk of 8 more invasive breast cancers per 10,000 women-years in the group treated with CE/MPA. Observational studies have also reported an increased risk of breast cancer in women using estrogen/progestin, with a smaller increased risk for estrogen alone.
The risk of endometrial cancer among unopposed estrogen users is about 2 to 12- fold greater than in non-users. Most studies have shown no significant increased risk with use for less than 1 year, but an increased risk of 15 to 24-fold with use for 5 to 10 years or more, persisting for at least 8 to 15 years after estrogen therapy is discontinued.
In the Women's Health Initiative study (WHI), an increase myocardial infarctions and strokes was observed in women receiving conjugated estrogens compared to placebo; a substudy of the WHI in which women were receiving conjugated estrogen plus progestin, showed an increased risk of coronary heart disease (CHD) events (defined as nonfatal myocardial infarction and CHD death) compared to placebo (37 vs 30 per 10,000 women-years). This increase was observed in year one and persisted. In a clinical trial of secondary prevention of cardiovascular disease (Heart and Estrogen/Progestin Replacement study; HERS) in postmenopausal women with documented heart disease (n = 2,763, average age 66.7 years) use of conjugated estrogens with progestin demonstrated no cardiovascular benefit.
A substudy of the WHI showed a 2-fold greater rate of venous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism, in women receiving conjugated estrogen with medroxyprogesterone compared to women receiving placebo. The rate of VTE was 34 per 10,000 women-years compared to 16 per 10,000 women-years in the placebo group. This increase risk was observed during the first year and persisted.
Frequency not reported: Deep and superficial venous thrombosis, pulmonary embolism, thrombophlebitis, myocardial infarction, stroke, increase in blood pressure
Frequency not reported: Changes in vaginal bleeding pattern, abnormal withdrawal bleeding or flow, breakthrough bleeding, spotting, dysmenorrhea, increase in size of uterine leiomyomata, vaginitis, including vaginal candidiasis, change in amount of cervical secretion, changes in cervical ectropion, endometrial hyperplasia, premenstrual like syndrome, amenorrhea during and after treatment; cystitis like syndrome
There are more reports of hepatic tumors occurring in women taking long-term oral contraceptives, but there are some reports in women taking isolated estrogen therapy.
Frequency not reported: Benign hepatic adenomas, hepatic hemangiomas
Frequency not reported: Mental depression, nervousness, mood disturbances, irritability
Frequency not reported: Retinal vascular thrombosis, steepening of corneal curvature, intolerance to contact lenses
Frequency not reported: Increased levels of thyroxin-binding globulin, breast tenderness, enlargement, pain, nipple discharge, galactorrhea, fibrocystic breast changes
Frequency not reported: Arthralgias, leg cramps
Frequency not reported: Exacerbation of asthma
1. "Product Information. Menest (esterified estrogens)." Pfizer U.S. Pharmaceuticals Group, New York, NY.
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Some side effects may not be reported. You may report them to the FDA.