Medically reviewed by Drugs.com. Last updated on Jan 18, 2020.
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- Conjugated Estrogen
- Estrogenic Substances, Conjugated
- Oestrogens, Conjugated/Equine
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Injection:
Premarin: 25 mg (1 ea)
Premarin: 0.3 mg [contains fd&c blue #2 (indigotine), fd&c yellow #10 (quinoline yellow)]
Premarin: 0.45 mg [contains fd&c blue #2 (indigotine)]
Premarin: 0.625 mg [contains fd&c blue #2 (indigotine), fd&c red #40]
Premarin: 0.9 mg
Premarin: 1.25 mg [contains fd&c yellow #10 (quinoline yellow), fd&c yellow #6 (sunset yellow)]
Brand Names: U.S.
- Estrogen Derivative
Conjugated estrogens contain a mixture of estrone sulfate, equilin sulfate, 17 alpha-dihydroequilin, 17 alpha-estradiol and 17 beta-dihydroequilin. Estrogens are responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Estradiol is the principle intracellular human estrogen and is more potent than estrone and estriol at the receptor level; it is the primary estrogen secreted prior to menopause. Following menopause, estrone and estrone sulfate are more highly produced. Estrogens modulate the pituitary secretion of gonadotropins, luteinizing hormone, and follicle-stimulating hormone through a negative feedback system; estrogen replacement reduces elevated levels of these hormones in postmenopausal women.
Widely distributes throughout the body; sex hormone target organs contain higher concentrations
Hepatic via CYP3A4; estradiol is converted to estrone and estriol; estrone is also converted to estriol and is converted to estradiol (Note: A dynamic equilibrium of metabolic interconversions between estrogens exists in the circulation); also undergoes enterohepatic recirculation (avoided with vaginal administration); estrone sulfate is the main metabolite in postmenopausal women
Urine (primarily estriol, also as estradiol, estrone, and conjugates)
Time to Peak
Total estrone: 7 hours
Total estrone: 27 hours
Binds to sex-hormone-binding globulin and albumin
Use: Labeled Indications
Abnormal uterine bleeding (injection only): Treatment of abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology.
Limitations of use: For short term use only to provide a rapid and temporary increase in estrogen levels.
Breast cancer, metastatic: Treatment of breast cancer (palliation) in appropriately selected men and postmenopausal women.
Hypoestrogenism (female): Treatment of hypoestrogenism due to hypogonadism, castration, or primary ovarian failure.
Osteoporosis prevention (female): Prevention of postmenopausal osteoporosis.
Limitations of use: For use only in women at significant risk of osteoporosis; consider use of nonestrogen medications.
Prostate cancer, advanced: Treatment of androgen-dependent prostatic cancer (palliation).
Vasomotor symptoms associated with menopause: Treatment of moderate to severe vasomotor symptoms associated with menopause.
Vulvar and vaginal atrophy associated with menopause: Treatment of moderate to severe vulvar and vaginal atrophy due to menopause.
Limitations of use: When used solely for the treatment of vulvar and vaginal atrophy, topical vaginal products should be considered.
Note: The International Society for the Study of Women’s Sexual Health and The North American Menopause Society have endorsed the term genitourinary syndrome of menopause (GSM) as new terminology for vulvovaginal atrophy. The term GSM encompasses all genital and urinary signs and symptoms associated with a loss of estrogen due to menopause (Portman 2014).
Off Label Uses
Data from one small randomized, double blind, placebo-controlled, crossover study in patients with chronic renal failure receiving hemodialysis and a history of bleeding, one small randomized, double blind, placebo-controlled, single center, crossover study in end-stage renal disease receiving hemodialysis without a history of bleeding, and one prospective, controlled single center study support the use of conjugated estrogens as an alternative treatment in the management of uremic bleeding due to the ability to shorten bleeding time [Heistinger 1990], [Livio 1986], [ Viganò 1988]. Clinical experience also suggests the utility of conjugated estrogens in the management of uremic bleeding [Hedges 2007]. Additional trials may be necessary to further define the role of conjugated estrogens in this setting.
Angioedema or anaphylactic reaction to estrogens or any component of the formulation; undiagnosed abnormal genital bleeding; DVT or PE (current or history of); active or history of arterial thromboembolic disease (eg, stroke, MI); breast cancer (except in appropriately selected patients being treated for metastatic disease); estrogen-dependent tumor (known or suspected); hepatic impairment or disease; known protein C, protein S, antithrombin deficiency or other known thrombophilic disorders; pregnancy
Canadian labeling: Additional contraindications (not in US labeling): Endometrial hyperplasia; partial or complete vision loss due to ophthalmic vascular disease; migraine with or without aura
General dosing guidelines: When treating symptoms of menopause, hormone therapy should be evaluated routinely for appropriate dose, duration, and route of administration for each individual patient based on treatment goals, risk factors, and overall health (NAMS 2017). Combined estrogen/progestin therapy is indicated for postmenopausal persons with a uterus to decrease the risk of endometrial cancer. Individuals who have had a hysterectomy generally do not need a progestin; however, one may be needed if there is a history of endometriosis. Adjust dose based on patient response.
Abnormal uterine bleeding: Acute/heavy bleeding: IM, IV: 25 mg, may repeat in 6-12 hours if needed (manufacturer's labeling) or 25 mg IV repeated every 4 to 6 hours for 24 hours (ACOG 557 2013).
Breast cancer, metastatic: Oral: Males and postmenopausal females: 10 mg 3 times/day for at least 3 months
Hypoestrogenism (female) due to castration or primary ovarian failure: Oral: 1.25 mg/day given cyclically*; adjust according to severity of symptoms and patient response. For maintenance, adjust to the lowest effective dose.
Hypoestrogenism (female) due to hypogonadism: Oral: 0.3 or 0.625 mg/day given cyclically*; dose may be titrated in 6- to 12-month intervals; progestin treatment should be added to maintain bone mineral density once skeletal maturity is achieved.
Osteoporosis prevention (females): Oral: Initial: 0.3 mg/day cyclically* or daily, depending on medical assessment of patient. Dose may be adjusted based on bone mineral density and clinical response. The lowest effective dose should be used.
Prostate cancer, advanced: Oral: 1.25 to 2.5 mg 3 times/day
Uremic bleeding (off-label use): IV: 0.6 mg/kg/day for 5 days (Heistinger 1990; Livio 1986; Viganò 1988)
Vasomotor symptoms associated with menopause: Oral: Initial: 0.3 mg/day. May be given cyclically* or daily, depending on medical assessment of patient. Adjust dose based on patient's response. The lowest dose that will control symptoms should be used.
Vulvar and vaginal atrophy associated with menopause: Oral: Initial: 0.3 mg/day. The lowest dose that will control symptoms should be used. May be given cyclically* or daily, depending on medical assessment of patient. Adjust dose based on patient's response.
*Cyclic administration: Either 3 weeks on, 1 week off or 25 days on, 5 days off
Note: Women >65 years of age should be assessed for benefits and risks of treatment; possible adjustments to safer lower-dose and/or route of administration should be considered (ACOG 565 2013; NAMS 2017). The Beers Criteria recommends avoiding systemic estrogen therapy in patients ≥65 years of age (independent of diagnosis or condition) (Beers Criteria [AGS 2019]).
Refer to adult dosing.
Constitutional delay of growth and puberty (CDGP) (females): Limited data available: Note: Begin with the lowest available dose and gradually increase. Obtain bone age every 6 months to avoid premature epiphyseal closure. If treatment continues beyond 1 year or breast growth is significant and has plateaued or breakthrough bleeding occurs, add cyclic progesterone. Continue until menstruation has been established, or longer if clinically indicated (Palmert 2012; Santos 2014; Sperling 2014).
Adolescents: Oral: Initial: 0.3 mg once daily; continue for 6 to 12 months then evaluate serum parameters and adjust accordingly; if a lower dose needed, consider a different estrogen preparation; requirements may change over the course of puberty; duration of therapy variable; once bone age advanced, may consider discontinuation of therapy (patient may continue pubertal advancement on own) (Melmed 2011). Note: Use of other estrogens (eg, estradiol) is preferred; if conjugated estrogens deemed necessary, the transdermal route may be preferred due to observed cardiovascular risks in post-menopausal females with the systemic route (Melmed 2011; Palmert 2012).
Dysfunctional uterine bleeding: Limited data available: Adolescents: IV: 25 mg every 4 to 6 hours for 24 hours (ACOG 557 2013); if patient hemodynamically unstable, may consider doses every 3 to 4 hours for 3 to 4 doses (Sperling 2014)
Hypogonadism, hypoestrogenism (females): Limited data available: Note: Begin with the lowest available dose and gradually increase dose over 2 to 3 years. Obtain bone age every 6 months to avoid premature epiphyseal closure. As puberty progresses, cyclic progesterone will need added (Palmert 2012; Santos 2014; Sperling 2014).
Children ≥12 years and Adolescents: Oral: Initial: 0.3 mg once daily, titrate at 6 to 12 months intervals to 0.45 mg once daily and then 0.625 mg once daily. After the first 4 to 6 months of therapy or once breakthrough bleeding occurs, estrogen should be switched from continuous to cyclic therapy and administered for the first 21 days of the month in combination with periodic progesterone (Melmed 2011; Palmert 2012). Overall estrogen replacement will be of extended duration and in some cases lifelong; experts suggest transitioning to transdermal estradiol therapy when able. Some experts suggest an initial dose of 0.1625 mg once daily and then titrating upwards every 6 to 12 months (0.3, 0.45, 0.625 mg once daily, respectively); however, an appropriate commercially available dosage form is not available in the US (Palmert 2012). Note: Use of other estrogens (eg, estradiol) is preferred; if conjugated estrogens deemed necessary, the transdermal route may be preferred due to observed cardiovascular risks in post-menopausal females with the systemic route (Melmed 2011; Norjavaara 2016; Palmert 2012).
Turner syndrome: Limited data available: Note: Estradiol is preferable to initiate hormone replacement therapy in females with Turner syndrome (particularly transdermal route); therapy is initiated around 12 years of age, and slowly increased over 2 to 4 years to adult estrogen levels; once achieved may consider transition to conjugated estrogens although transdermal preferred (Bondy 2007; Gawlik 2016). Adolescents ≥14 years: Usual dose: 1.25 to 2.5 mg once daily; reported range: 0.625 to 2.5 mg; adjust dose based on response and serum parameters (Bondy 2007; Gawlik 2016; Kodama 2012).
Injection: Reconstitute with sterile water for injection; slowly inject diluent against side wall of the vial. Agitate gently; do not shake violently.
Injection: May be administered IV or IM; when administered IV, drug should be administered slowly to avoid the occurrence of a flushing reaction
Oral tablet: Administer at the same time each day. May be administered without regard to meals.
Vasomotor symptoms associated with menopause: Recently menopausal women (<2 years) with a uterus may benefit from a cyclic regimen (continuous regimens may be associated with unscheduled bleeding) (ES [Stuenkel 2015]).
Ensure adequate calcium and vitamin D intake when used for the prevention of osteoporosis. Powder for reconstitution for injection (25 mg) contains lactose 200 mg.
Injection: Refrigerate at 2°C to 8°C (36°F to 46°F) prior to reconstitution. Use immediately following reconstitution.
Tablets: Store at room temperature 20°C to 25°C (68°F to 77°F).
Ajmaline: Estrogen Derivatives may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy
Anastrozole: Estrogen Derivatives may diminish the therapeutic effect of Anastrozole. Avoid combination
Anthrax Immune Globulin (Human): Estrogen Derivatives may enhance the thrombogenic effect of Anthrax Immune Globulin (Human). Monitor therapy
Anticoagulants: Estrogen Derivatives may diminish the anticoagulant effect of Anticoagulants. More specifically, the potential prothrombotic effects of some estrogens and progestin-estrogen combinations may counteract anticoagulant effects. Management: Carefully weigh the prospective benefits of estrogens against the potential increased risk of procoagulant effects and thromboembolism. Use is considered contraindicated under some circumstances. Refer to related guidelines for specific recommendations. Consider therapy modification
Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy
Ascorbic Acid: May increase the serum concentration of Estrogen Derivatives. Monitor therapy
Bosentan: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
C1 inhibitors: Estrogen Derivatives may enhance the thrombogenic effect of C1 inhibitors. Monitor therapy
Chenodiol: Estrogen Derivatives may diminish the therapeutic effect of Chenodiol. Management: Monitor clinical response to chenodiol closely when used together with any estrogen derivative. Monitor therapy
CloZAPine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of CloZAPine. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy
Corticosteroids (Systemic): Estrogen Derivatives may increase the serum concentration of Corticosteroids (Systemic). Monitor therapy
Cosyntropin: Estrogen Derivatives may diminish the diagnostic effect of Cosyntropin. Management: Discontinue estrogen containing drugs 4 to 6 weeks prior to cosyntropin (ACTH) testing. Consider therapy modification
CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification
CYP3A4 Inhibitors (Moderate): May increase the serum concentration of Estrogen Derivatives. Monitor therapy
CYP3A4 Inhibitors (Strong): May increase the serum concentration of Estrogen Derivatives. Monitor therapy
Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification
Dantrolene: Estrogen Derivatives may enhance the hepatotoxic effect of Dantrolene. Monitor therapy
Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Dehydroepiandrosterone: May enhance the adverse/toxic effect of Estrogen Derivatives. Avoid combination
Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification
Erdafitinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Exemestane: Estrogen Derivatives may diminish the therapeutic effect of Exemestane. Avoid combination
Hemin: Estrogen Derivatives may diminish the therapeutic effect of Hemin. Avoid combination
Herbs (Estrogenic Properties): May enhance the adverse/toxic effect of Estrogen Derivatives. Monitor therapy
Hyaluronidase: Estrogen Derivatives may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving estrogens (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. Consider therapy modification
Immune Globulin: Estrogen Derivatives may enhance the thrombogenic effect of Immune Globulin. Monitor therapy
Indium 111 Capromab Pendetide: Estrogen Derivatives may diminish the diagnostic effect of Indium 111 Capromab Pendetide. Avoid combination
Ivosidenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
LamoTRIgine: Estrogen Derivatives may decrease the serum concentration of LamoTRIgine. Monitor therapy
Lenalidomide: Estrogen Derivatives may enhance the thrombogenic effect of Lenalidomide. Monitor therapy
Lorlatinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Avoid concurrent use of lorlatinib with any CYP3A4 substrates for which a minimal decrease in serum concentrations of the CYP3A4 substrate could lead to therapeutic failure and serious clinical consequences. Consider therapy modification
Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification
Mivacurium: Estrogen Derivatives may increase the serum concentration of Mivacurium. Monitor therapy
Nonsteroidal Anti-Inflammatory Agents (COX-2 Selective): May enhance the thrombogenic effect of Estrogen Derivatives. Nonsteroidal Anti-Inflammatory Agents (COX-2 Selective) may increase the serum concentration of Estrogen Derivatives. Monitor therapy
Ospemifene: Estrogen Derivatives may enhance the adverse/toxic effect of Ospemifene. Estrogen Derivatives may diminish the therapeutic effect of Ospemifene. Avoid combination
Pomalidomide: May enhance the thrombogenic effect of Estrogen Derivatives. Management: Canadian pomalidomide labeling recommends caution with use of hormone replacement therapy and states that hormonal contraceptives are not recommended. US pomalidomide labeling does not contain these specific recommendations. Consider therapy modification
ROPINIRole: Estrogen Derivatives may increase the serum concentration of ROPINIRole. Monitor therapy
Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Somatropin: Estrogen Derivatives may diminish the therapeutic effect of Somatropin. Shown to be a concern with oral hormone replacement therapy in postmenopausal women. Management: Monitor for reduced growth hormone efficacy. A larger somatropin dose may be required to reach treatment goal. This interaction does not appear to apply to non-orally administered estrogens (e.g., transdermal, vaginal ring). Consider therapy modification
Succinylcholine: Estrogen Derivatives may increase the serum concentration of Succinylcholine. Monitor therapy
Thalidomide: Estrogen Derivatives may enhance the thrombogenic effect of Thalidomide. Monitor therapy
Theophylline Derivatives: CYP1A2 Inhibitors (Weak) may increase the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline. Monitor therapy
Thyroid Products: Estrogen Derivatives may diminish the therapeutic effect of Thyroid Products. Monitor therapy
Tipranavir: Estrogen Derivatives may enhance the dermatologic adverse effect of Tipranavir. The combination of tipranavir/ritonavir and ethinyl estradiol/norethindrone was associated with a high incidence of skin rash. Tipranavir may decrease the serum concentration of Estrogen Derivatives. Management: Women using hormonal contraceptives should consider alternative, non-hormonal forms of contraception. Consider therapy modification
TiZANidine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use is necessary, initiate tizanidine at an adult dose of 2 mg and increase in 2 to 4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions. Consider therapy modification
Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Ursodiol: Estrogen Derivatives may diminish the therapeutic effect of Ursodiol. Monitor therapy
Reduced response to metyrapone test.
Percentages reported in postmenopausal women following oral use.
Central nervous system: Headache (26% to 32%), pain (17% to 20%)
Gastrointestinal: Abdominal pain (15% to 17%)
Genitourinary: Vaginal hemorrhage (2% to 14%), mastalgia (7% to 12%)
Neuromuscular & skeletal: Back pain (13% to 14%), arthralgia (7% to 14%)
Respiratory: Pharyngitis (10% to 12%), sinusitis (6% to 11%)
1% to 10%:
Central nervous system: Depression (5% to 8%), dizziness (4% to 6%), nervousness (2% to 5%)
Dermatologic: Pruritus (4% to 5%)
Gastrointestinal: Diarrhea (6% to 7%), flatulence (6% to 7%)
Genitourinary: Vaginitis (5% to 7%), leukorrhea (4% to 7%), vulvovaginal candidiasis (5% to 6%)
Neuromuscular & skeletal: Weakness (7% to 8%), leg cramps (3% to 7%)
Respiratory: Increased cough (4% to 7%)
Frequency not defined (injection): Local: Injection site phlebitis, pain at injection site, swelling at injection site
<1%, postmarketing, and/or case reports: Abnormal uterine bleeding, alopecia, anaphylaxis, angioedema, bloating, breast hypertrophy, breast tenderness, cerebrovascular accident, change in cervical secretions, change in libido, chloasma, cholestatic jaundice, contact lens intolerance, decreased glucose tolerance, deep vein thrombosis, dementia, dysmenorrhea, edema, endometrial carcinoma, endometrial hyperplasia, erythema multiforme, erythema nodosum, exacerbation of asthma, exacerbation of epilepsy, exacerbation of hepatic hemangioma, exacerbation of porphyria, fibrocystic breast changes, galactorrhea, gallbladder disease, growth potentiation of benign meningioma, gynecomastia, hirsutism, hypersensitivity reaction, hypertension, increased serum triglycerides, irritability, ischemic colitis, malignant neoplasm of breast, migraine, mood changes, myocardial infarction, nausea, nipple discharge, ovarian carcinoma, pancreatitis, pelvic pain, pulmonary embolism, retinal thrombosis, skin rash, superficial venous thrombosis, thrombophlebitis, urticaria, uterine fibroids (increased size), vomiting, vulvovaginal candidiasis, weight changes
ALERT: U.S. Boxed WarningEndometrial cancer:
There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be taken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal genital bleeding.Cardiovascular disease:
Estrogen-alone therapy should not be used for the prevention of cardiovascular disease. The Women's Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral conjugated estrogens 0.625 mg alone, relative to placebo.
Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease. The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism (PE), stroke, and myocardial infarction (MI) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral conjugated estrogens (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg), relative to placebo.Breast cancer:
The WHI estrogen-plus-progestin substudy demonstrated an increased risk of invasive breast cancer.Dementia:
Estrogen-alone therapy should not be used for the prevention of dementia. The WHI Memory Study (WHIMS) estrogen-alone ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 5.2 years of treatment with daily conjugated estrogens (0.625 mg) alone, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women.
Estrogen plus progestin therapy should not be used for the prevention of dementia. The WHIMS estrogen plus progestin ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily conjugated estrogens (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg), relative to placebo. It is unknown whether this finding applies to younger postmenopausal women.Risk vs benefit:
In the absence of comparable data, these risks should be assumed to be similar for other doses of conjugated estrogens (with or without medroxyprogesterone acetate) and other dosage forms of estrogens (with or without progestins). 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.
Concerns related to adverse effects:
• Anaphylaxis: Anaphylaxis requiring emergency medical management has been reported within minutes to hours of taking conjugated estrogen (CE) tablets. Angioedema involving the face, feet, hands, larynx, and tongue has also been reported.
• Breast cancer: [US Boxed Warning]: Based on data from the Women’s Health Initiative (WHI) studies, an increased risk of invasive breast cancer was observed in postmenopausal women using conjugated estrogens (CE) in combination with medroxyprogesterone acetate (MPA). Observational studies noted this risk declines once therapy is discontinued. The WHI study did not observe an increased risk of invasive breast cancer in women with a hysterectomy using CE alone. The risk of breast cancer in postmenopausal patients on hormone therapy may depend upon type of estrogen and/or progestin, dose, timing of therapy initiation, duration of therapy, route of administration, and individual patient characteristics (AACE/ACE [Cobin 2017]; NAMS 2017). Hormone therapy may be associated with increased breast density (NAMS 2017); an increase in abnormal mammogram findings requiring further evaluation has been reported with estrogen alone or in combination with progestin therapy. Estrogen use may lead to severe hypercalcemia in patients with breast cancer and bone metastases; discontinue estrogen if hypercalcemia occurs.
• Dementia: [US Boxed Warning]: Estrogens with or without progestin should not be used to prevent dementia. In the Women’s Health Initiative Memory Study (WHIMS), an increased incidence of probable dementia was observed in women ≥65 years of age taking CE alone or in combination with MPA. Because the WHI memory studies were conducted in women ≥65 years of age, it is unknown if these findings apply to younger postmenopausal women. However, hormone therapy is not recommended at any age to prevent or treat cognitive decline or dementia (AACE [Goodman 2011]; NAMS 2017).
• Endometrial cancer: [US Boxed Warning]: The use of unopposed estrogen in women with a uterus is associated with an increased risk of endometrial cancer. The addition of a progestin to estrogen therapy may decrease the risk of endometrial hyperplasia, a precursor to endometrial cancer. Adequate diagnostic measures, including endometrial sampling if indicated, should be performed to rule out malignancy in postmenopausal women with undiagnosed abnormal vaginal bleeding. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens at equivalent estrogen doses. The risk of endometrial cancer appears to be dose and duration dependent, greatest with use ≥5 years, and may persist following discontinuation of therapy. The use of a progestin is not generally required when low doses of estrogen are used locally for vaginal atrophy, although long term data (>1 year) supporting this recommendation are lacking (NAMS 2013; NAMS 2017).
• Endometriosis: Estrogens may exacerbate endometriosis. Malignant transformation of residual endometrial implants has been reported posthysterectomy with unopposed estrogen therapy. Consider adding a progestin in women with residual endometriosis posthysterectomy.
• Lipid effects: Estrogen compounds are generally associated with lipid effects such as increased HDL-cholesterol and decreased LDL-cholesterol. Triglycerides may also be increased in women with preexisting hypertriglyceridemia; discontinue if pancreatitis occurs. Use with caution in patients with familial defects of lipoprotein metabolism.
• Ovarian cancer: Available information related to the use of menopausal estrogen or estrogen/progestin therapy and risk of ovarian cancer is inconsistent. If an association is present, the absolute risk is likely rare and may be influenced by duration of therapy (AACE [Goodman 2011]; ES [Stuenkel 2015]; NAMS 2017).
• Retinal vascular thrombosis: Estrogens may cause retinal vascular thrombosis; discontinue if migraine, loss of vision, proptosis, diplopia, or other visual disturbances occur; discontinue permanently if papilledema or retinal vascular lesions are observed on examination.
• Asthma: Use caution in patients with asthma; may exacerbate disease.
• Carbohydrate intolerance: May impair glucose tolerance; use caution in patients with diabetes. Prior to therapy, consider age, cardiovascular and metabolic risk factors in patients previously diagnosed with diabetes (AACE/ACE [Cobin 2017]).
• Cardiovascular disease: [US Boxed Warning]: Estrogens with or without progestin should not be used to prevent cardiovascular disease. Using data from the Women’s Health Initiative (WHI) studies, an increased risk of deep vein thrombosis (DVT) and stroke has been reported with CE and an increased risk of DVT, stroke, pulmonary emboli (PE) and myocardial infarction (MI) has been reported with CE with MPA in postmenopausal women 50 to 79 years of age. Additional risk factors include diabetes mellitus, hypercholesterolemia, hypertension, SLE, obesity, tobacco use, and/or history of venous thromboembolism (VTE). Risk factors should be managed appropriately; discontinue use immediately if adverse cardiovascular events occur or are suspected. Due to possible lower risk of thrombotic events, transdermal administration may be preferred for treating vasomotor symptoms of menopause in patients with risk factors for cardiovascular disease (AACE/ACE [Cobin 2017]; ACOG 556 2013; ES [Stuenkel 2015]). Use is contraindicated in women with active DVT, PE, arterial thromboembolic disease (stroke and MI), or a history of these conditions.
• Diseases exacerbated by fluid retention: Use with caution in patients with diseases which may be exacerbated by fluid retention, including cardiac or renal dysfunction.
• Epilepsy: Use caution with epilepsy; may exacerbate disease.
• Gallbladder disease: Use of postmenopausal estrogen may be associated with an increased risk of gallbladder disease requiring surgery.
• Hepatic dysfunction: Estrogens are poorly metabolized in patients with hepatic dysfunction. Use caution with a history of cholestatic jaundice associated with prior estrogen use or pregnancy. Discontinue if jaundice develops or if acute or chronic hepatic disturbances occur. Use is contraindicated with hepatic impairment or disease.
• Hepatic hemangiomas: Use with caution in patients with hepatic hemangiomas; may exacerbate disease.
• Hereditary angioedema: Exogenous estrogens may exacerbate angioedema symptoms in women with hereditary angioedema.
• Hypoparathyroidism: Use caution in patients with hypoparathyroidism; estrogen-induced hypocalcemia may occur.
• Migraine: Use caution with migraine; may exacerbate disease.
• Porphyria: Use with caution in patients with porphyria; may exacerbate disease.
• SLE: Use with caution in patients with SLE; may exacerbate disease.
Concurrent drug therapy issues:
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information
• Thyroid replacement therapy: Estrogens may increase thyroid-binding globulin (TBG) levels leading to increased circulating total thyroid hormone levels. Women on thyroid replacement therapy may require higher doses of thyroid hormone while receiving estrogens.
• Pediatric: Prior to puberty, estrogens may cause premature closure of the epiphyses. Premature breast development, vaginal bleeding and vaginal cornification may be induced in girls. Modification of the normal puberty process may occur in boys.
• Surgical patients: Whenever possible, estrogens should be discontinued at least 4-6 weeks prior to elective surgery associated with an increased risk of thromboembolism or during periods of prolonged immobilization.
Dosage form specific issues:
• Injection: Although the injection is indicated for short term use only, all warnings and precautions associated with oral administration should be considered.
• Duration of use: Extended use of menopausal hormone therapy may be considered for persistent vasomotor symptoms, issues related to quality of life, or for osteoporosis prevention in women at increased risk of fracture. Menopausal hormonal therapy does not need to be routinely discontinued in women >60 years of age and may continue in women >65 years of age after clinical evaluation and discussion of benefits and risks of treatment. Annual exams should be performed with a review of comorbidities; possible adjustments to safer lower-dose and/or route of administration should be discussed (ACOG 565 2013; NAMS 2017).
• Genitourinary syndrome of menopause: Low dose vaginal estrogen is preferred over systemic therapy for GSM in the absence of vasomotor symptoms due to increased efficacy and decreased systemic effects (eg, cardiovascular effects, cancer risk) (Crandall 2018; NAMS 2013; NAMS 2017).
• Laboratory changes: The use of estrogens and/or progestins may change the results of some laboratory tests (eg, coagulation factors, lipids, glucose tolerance, binding proteins). The dose, route, and the specific estrogen/progestin influence these changes.
• Osteoporosis use: In women with premature menopause, hormone therapy to prevent bone loss may be used unless otherwise contraindicated; therapy should be reassessed when the average age of menopause is reached. It is also an appropriate bone-active therapy for women with vasomotor symptoms who are <60 years of age or within 10 years of menopause onset. Use may be considered for women at high risk of fractures who are not candidates for other osteoporosis therapies (NAMS 2017).
• Risks vs benefits: When used for the relief of menopausal symptoms or increased risk of bone fracture/loss, the benefit-risk of hormone therapy is most favorable if started in patients who have no contraindications to therapy, are <60 years of age, within 10 years of menopause onset, have a favorable lipid profile, and do not have the factor V Leiden genotype or metabolic syndrome. Risk factors for cardiovascular disease should also be considered when evaluating therapy and route of administration (AACE/ACE [Cobin 2017]; NAMS 2017). [US Boxed Warning]: Estrogens with or without progestin should be used for the shortest duration possible at the lowest effective dose consistent with treatment goals and risks for the individual woman. Patients should be reevaluated as clinically appropriate to determine if treatment is still necessary. Available data related to treatment risks are from Women’s Health Initiative (WHI) studies, which evaluated oral CE 0.625 mg with or without MPA 2.5 mg relative to placebo in postmenopausal women. Other combinations and dosage forms of estrogens and progestins were not studied. Outcomes reported from clinical trials using CE with or without MPA should be assumed to be similar for other doses and other dosage forms of estrogens and progestins until comparable data becomes available.
Prior to therapy, baseline risk for breast cancer and CVD. During therapy, age appropriate breast and pelvic exams; blood pressure; unscheduled bleeding lasting >6 months for endometrial pathology (sooner in patients who are obese, diabetic, or have a history of endometrial cancer); serum triglycerides (2 weeks after starting therapy in patients with baseline level >200 mg/dL); TSH (6 to 12 weeks after starting oral therapy in patients taking thyroid replacement) (ES [Stuenkel 2015]).
Menopausal symptoms: Efficacy beginning 1 to 3 months after starting therapy, then every 6 to 12 months as appropriate. Duration of treatment should be evaluated at least annually (ES [Stuenkel 2015]).
Note: Monitoring of FSH and serum estradiol is not useful when managing vasomotor symptoms or GSM.
Abnormal uterine bleeding: Response to treatment that may be dependent upon etiology of bleed (ACOG 557 2013; Haamid 2017).
Prevention of osteoporosis: Bone density measurement
Uremic bleeding: Bleeding time
Use is contraindicated during pregnancy.
Estrogens are not indicated for use during pregnancy or immediately postpartum. In general, the use of estrogen and progestin as in combination hormonal contraceptives have not been associated with teratogenic effects when inadvertently taken early in pregnancy.
What is this drug used for?
• It is used to add estrogen to the body when the ovaries have been taken out or do not work the right way.
• It is used to put off soft, brittle bones (osteoporosis) in women after change of life.
• It is used to prevent or lower the signs of the change of life (menopause).
• It is used to treat vaginal bleeding.
• Rarely, it is used to treat breast or prostate cancers.
• It may be given to you for other reasons. Talk with the doctor.
Frequently reported side effects of this drug
• Hair loss
• Enlarged breasts
• Leg cramps
• Abdominal cramps
• Injection site irritation
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
• Gallstones like pain in the upper right abdominal area, right shoulder area, or between the shoulder blades; yellow skin; or fever with chills.
• Severe cerebrovascular disease like change in strength on one side is greater than the other, difficulty speaking or thinking, change in balance, or vision changes.
• Blood clots like numbness or weakness on one side of the body; pain, redness, tenderness, warmth, or swelling in the arms or legs; change in color of an arm or leg; chest pain; shortness of breath; fast heartbeat; or coughing up blood.
• Liver problems like dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin.
• Pancreatitis like severe abdominal pain, severe back pain, severe nausea, or vomiting
• Change in sex drive
• Severe headache
• Severe dizziness
• Passing out
• Pelvic pain
• Vision changes
• Bulging eyes
• Contact lens discomfort
• Lump in breast
• Breast soreness or pain
• Nipple discharge
• Abnormal vaginal bleeding
• Vaginal pain, itching, and discharge
• Mood changes
• Trouble with memory
• Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
More about conjugated estrogens
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- 74 Reviews
- Drug class: estrogens
- Estrogens (Conjugated A/Synthetic) (Wolters Kluwer)
- Estrogens (Conjugated B/Synthetic) (Wolters Kluwer)