Enjuvia

Name: Enjuvia

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What should I avoid while taking conjugated estrogens?

Do not smoke while using this medication. Smoking can increase your risk of blood clots, stroke, or heart attack caused by conjugated estrogens.

Before Using Enjuvia

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Use of this medicine before puberty is not recommended. Growth of bones can be stopped early. Girls and boys may develop growth of breasts. Girls may have vaginal changes, including vaginal bleeding.

This medicine may be used to start puberty in teenagers with some types of delayed puberty.

Geriatric

Elderly people are especially sensitive to the effects of estrogens. This may increase the chance of side effects during treatment, especially stroke, invasive breast cancer, and memory problems.

Pregnancy

Estrogens are not recommended for use during pregnancy or right after giving birth. Becoming pregnant or maintaining a pregnancy is not likely to occur around the time of menopause.

Certain estrogens have been shown to cause serious birth defects in humans and animals. Some daughters of women who took diethylstilbestrol (DES) during pregnancy have developed reproductive (genital) tract problems and, rarely, cancer of the vagina or cervix (opening to the uterus) when they reached childbearing age. Some sons of women who took DES during pregnancy have developed urinary-genital tract problems.

Breast Feeding

Use of this medicine is not recommended in nursing mothers. Estrogens pass into the breast milk and their possible effect on the baby is not known.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.

  • Dasabuvir
  • Ombitasvir
  • Paritaprevir
  • Ritonavir
  • Tranexamic Acid

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Anagrelide
  • Aprepitant
  • Boceprevir
  • Bosentan
  • Bupropion
  • Carbamazepine
  • Ceritinib
  • Conivaptan
  • Dabrafenib
  • Darunavir
  • Dasabuvir
  • Dexamethasone
  • Donepezil
  • Eliglustat
  • Enzalutamide
  • Fosphenytoin
  • Griseofulvin
  • Idelalisib
  • Isotretinoin
  • Lesinurad
  • Lixisenatide
  • Lumacaftor
  • Mitotane
  • Modafinil
  • Netupitant
  • Oxcarbazepine
  • Paclitaxel
  • Paclitaxel Protein-Bound
  • Phenytoin
  • Piperaquine
  • Pitolisant
  • Pixantrone
  • Prednisone
  • Rifabutin
  • Rifampin
  • St John's Wort
  • Sugammadex
  • Theophylline
  • Tizanidine
  • Topiramate
  • Valproic Acid

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

For all patients

  • Asthma or
  • Calcium, too much or too little in blood or
  • Diabetes or
  • Epilepsy or seizures or
  • Heart problems or
  • Kidney problems or
  • Liver tumors, benign or
  • Lupus erythematosus, systemic or
  • Migraine headaches—Estrogens may worsen these conditions.
  • Blood clotting problems, or history of during previous estrogen therapy—Estrogens usually are not used until blood clotting problems stop; using estrogens is not a problem for most patients without a history of blood clotting problems due to estrogen use.
  • Breast cancer or
  • Bone cancer or
  • Cancer of the uterus or
  • Fibroid tumors of the uterus—Estrogens may interfere with the treatment of breast or bone cancer or worsen cancer of the uterus when these conditions are present.
  • Bulging eyes or
  • Double vision or
  • Migraine headache or
  • Vision changes, sudden onset including or
  • Vision loss, partial or complete—Estrogens may cause these problems. Tell your doctor if you have had any of these problems, especially while taking estrogen or oral contraceptives (“birth control pills”).
  • Changes in genital or vaginal bleeding of unknown causes—Use of estrogens may delay diagnosis or worsen condition. The reason for the bleeding should be determined before estrogens are used.
  • Endometriosis or
  • Gallbladder disease or gallstones, or history of or
  • High cholesterol or triglycerides, or history of or
  • Liver disease, or history of or
  • Pancreatitis (inflammation of pancreas) or
  • Porphyria—Estrogens may worsen these conditions. Although estrogens can improve blood cholesterol, they can worsen blood triglycerides for some people.
  • Hypothyroid (too little thyroid hormone)—Dose of thyroid medicine may need to be increased.

For males treated for breast or prostate cancer:

  • Blood clots or
  • Heart or circulation disease or
  • Stroke—Males with these medical problems may be more likely to have clotting problems while taking estrogens; the high doses of estrogens used to treat male breast or prostate cancer have been shown to increase the chances of heart attack, phlebitis (inflamed veins) caused by a blood clot, or blood clots in the lungs.

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 or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • 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 high blood sugar like confusion, feeling sleepy, more thirst, more hungry, passing urine more often, flushing, fast breathing, or breath that smells like fruit.
  • Chest pain or pressure.
  • Shortness of breath.
  • Coughing up blood.
  • Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
  • Swelling, warmth, numbness, change of color, or pain in a leg or arm.
  • Feeling very tired or weak.
  • Very bad headache.
  • Very upset stomach or throwing up.
  • Very bad dizziness or passing out.
  • Change in eyesight.
  • Bulging eyes.
  • Change in how contact lenses feel in the eyes.
  • A lump in the breast, breast soreness, or nipple discharge.
  • Breast pain.
  • Vaginal itching or discharge.
  • Vaginal bleeding that is not normal.
  • Low mood (depression).
  • Memory problems or loss.
  • Swelling in hands or feet.
  • A burning, numbness, or tingling feeling that is not normal.

Warnings and Precautions

Cardiovascular Disorders

An increased risk of stroke and DVT has been reported with estrogen-alone therapy. An increased risk of PE, DVT, stroke, and MI has been reported with estrogen plus progestin therapy. Should any of these occur or be suspected, estrogen with or without progestin therapy should be discontinued immediately.

Risk factors for arterial vascular disease (for example, hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (VTE) (for example, personal history or family history of VTE, obesity, and systemic lupus erythematosus) should be managed appropriately.

Stroke

In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving CE (0.625 mg)-alone compared to women in the same age group receiving placebo (45 versus 33 per 10,000 women-years). The increase in risk was demonstrated in year 1 and persisted [seeClinical Studies (14.3)]. Should a stroke occur or be suspected, estrogen-alone therapy should be discontinued immediately.

Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving CE (0.625 mg)-alone versus those receiving placebo (18 versus 21 per 10,000 woman-years).1

In the WHI estrogen-plus-progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women in the same age group receiving placebo (33 versus 25 per 10,000 women-years) [seeClinical Studies (14.3)]. The increase in risk was demonstrated after the first year and persisted.1 Should a stroke occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.

Coronary Heart Disease

In the WHI estrogen-alone substudy, no overall effect on coronary heart disease (CHD) events (defined as non-fatal MI, silent MI, or CHD death) was reported in women receiving estrogen-alone compared to placebo2[see Clinical Studies (14.3)].

Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE [0.625 mg]-alone compared to placebo) in women with less than 10 years since menopause (8 versus 16 per 10,000 women-years).

In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of CHD events reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (41 versus 34 per 10,000 women-years).1 An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5 [see Clinical Studies (14.3)].

In postmenopausal women with documented heart disease (n = 2,763, average 66.7 years of age), in a controlled clinical trial of secondary prevention of cardiovascular disease (Heart and Estrogen/Progestin Replacement Study [HERS]), treatment with daily CE (0.625 mg) plus MPA (2.5 mg) demonstrated no cardiovascular benefit. During an average follow-up of 4.1 years, treatment with CE plus MPA did not reduce the overall rate of CHD events in postmenopausal women with established coronary heart disease. There were more CHD events in the CE plus MPA-treated group than in the placebo group in year 1, but not during the subsequent years. Two thousand, three hundred and twenty-one (2,321) women from the original HERS trial agreed to participate in an open-label extension of HERS, HERS II. Average follow-up in HERS II was an additional 2.7 years, for a total of 6.8 years overall. Rates of CHD events were comparable among women in the CE (0.625 mg) plus MPA (2.5 mg) group and the placebo group in HERS, HERS II, and overall.

Venous Thromboembolism

In the WHI estrogen-alone substudy, the risk of VTE (DVT and PE) was increased for women receiving daily CE (0.625 mg)-alone compared to placebo (30 versus 22 per 10,000 women-years), although only the increased risk of DVT reached statistical significance (23 versus 15 per 10,000 women years). The increase in VTE risk was demonstrated during the first 2 years3[seeClinical Studies (14.3)]. Should a VTE occur or be suspected, estrogen-alone therapy should be discontinued immediately.

In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE was reported in women receiving CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (35 versus 17 per 10,000 women-years). Statistically significant increases in risk for both DVT (26 versus 13 per 10,000 women-years) and PE (18 versus 8 per 10,000 women-years) were also demonstrated. The increase in VTE risk was demonstrated during the first year and persisted4[seeClinical Studies (14.3)]. Should a VTE occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.

If feasible, estrogens should be discontinued at least 4 to 6 weeks before surgery of the type associated with an increased risk of thromboembolism, or during periods of prolonged immobilization.

Malignant Neoplasms

Endometrial Cancer

An increased risk of endometrial cancer has been reported with the use of unopposed estrogen therapy in a woman with a uterus. The reported endometrial cancer risk among unopposed estrogen users is about 2 to 12 times greater than in non-users, and appears dependent on duration of treatment and on estrogen dose. Most studies show no significant increased risk associated with use of estrogens for less than 1 year. The greatest risk appears associated with prolonged use, with increased risks of 15- to 24-fold for 5 to 10 years or more, and this risk has been shown to persist for at least 8 to 15 years after estrogen therapy is discontinued.

Clinical surveillance of all women taking estrogen-alone or estrogen plus progestin therapy is important. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent estrogen dose. Adding a progestin to postmenopausal estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer.

Breast Cancer

The most important randomized clinical trial providing information about breast cancer in estrogen-alone users is the WHI substudy of daily CE (0.625 mg)-alone. In the WHI estrogen-alone substudy, after an average follow-up of 7.1 years daily CE-alone was not associated with an increased risk of invasive breast cancer (relative risk [RR] 0.80)5[seeClinical Studies (14.3)].

The most important randomized clinical trial providing information about breast cancer in estrogen plus progestin users is the WHI substudy of daily CE (0.625 mg) plus MPA (2.5 mg). After a mean follow-up of 5.6 years, the estrogen plus progestin substudy reported an increased risk of invasive breast cancer in women who took daily CE plus MPA. In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years, for CE plus MPA compared with placebo6[seeClinical Studies (14.3)]. Among women who reported prior use of hormone therapy, the relative risk of invasive breast cancer was 1.86, and the absolute risk was 46 versus 25 cases per 10,000 women-years, for CE plus MPA compared with placebo. Among women who reported no prior use of hormone therapy, the relative risk of invasive breast cancer was 1.09, and the absolute risk was 40 versus 36 cases per 10,000 women-years for CE plus MPA compared with placebo. In the same substudy, invasive breast cancers were larger, were more likely to be node positive, and were diagnosed at a more advanced stage in the CE (0.625 mg) plus MPA (2.5 mg) group compared with the placebo group. Metastatic disease was rare, with no apparent difference between the two groups. Other prognostic factors, such as histologic subtype, grade, and hormone receptor status did not differ between the groups [seeClinical Studies (14.3)].

Consistent with the WHI clinical trials, observational studies have also reported an increased risk of breast cancer for estrogen plus progestin therapy, and a smaller increased risk for estrogen-alone therapy, after several years of use. The risk increased with duration of use, and appeared to return to baseline over about 5 years after stopping treatment (only the observational studies have substantial data on risk after stopping). Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with estrogen plus progestin therapy as compared to estrogen-alone therapy. However, these studies have not found significant variation in the risk of breast cancer among different estrogen plus progestin combinations, doses, or routes of administration.

The use of estrogen-alone and estrogen plus progestin has been reported to result in an increase in abnormal mammograms requiring further evaluation.

All women should receive yearly breast examinations by a healthcare provider and perform monthly breast self-examinations. In addition, mammography examinations should be scheduled based on patient age, risk factors, and prior mammogram results.

Ovarian Cancer

The WHI estrogen plus progestin substudy reported a statistically non-significant increased risk of ovarian cancer. After an average follow-up of 5.6 years, the relative risk for ovarian cancer for CE plus MPA versus placebo was 1.58 (95 percent CI, 0.77-3.24). The absolute risk for CE plus MPA versus placebo was 4 versus 3 cases per 10,000 women-years.7 In some epidemiologic studies, the use of estrogen plus progestin and estrogen-only products, in particular for 5 or more years, has been associated with an increased risk of ovarian cancer. However, the duration of exposure associated with increased risk is not consistent across all epidemiologic studies, and some report no association.

Probable Dementia

In the WHIMS estrogen-alone ancillary study of WHI, a population of 2,947 hysterectomized women 65 to 79 years of age was randomized to daily CE (0.625 mg)-alone or placebo.

After an average follow-up of 5.2 years, 28 women in the estrogen-alone group and 19 women in the placebo group were diagnosed with probable dementia. The relative risk of probable dementia for CE-alone versus placebo was 1.49 (95 percent CI, 0.83-2.66). The absolute risk of probable dementia for CE-alone versus placebo was 37 versus 25 cases per 10,000 women-years8[seeUse in Specific Populations (8.5), and Clinical Studies (14.4)].

In the WHIMS estrogen plus progestin ancillary study, a population of 4,532 postmenopausal women 65 to 79 years of age was randomized to daily CE (0.625 mg) plus MPA (2.5 mg) or placebo.

After an average follow-up of four years, 40 women in the CE plus MPA group and 21 women in the placebo group were diagnosed with probable dementia. The relative risk of probable dementia for CE plus MPA versus placebo was 2.05 (95 percent CI, 1.21-3.48). The absolute risk of probable dementia for CE plus MPA versus placebo was 45 versus 22 cases per 10,000 women-years8[seeUse in Specific Populations (8.5), and Clinical Studies (14.4)].

When data from the two populations in the WHIMS estrogen-alone and estrogen plus progestin ancillary studies were pooled as planned in the WHIMS protocol, the reported overall relative risk for probable dementia was 1.76 (95 percent CI, 1.19-2.60). Since both ancillary studies were conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women8[seeUse in Specific Populations (8.5), and Clinical Studies (14.4)].

Gallbladder Disease

A 2 to 4-fold increase in the risk of gallbladder disease requiring surgery in postmenopausal women receiving estrogens has been reported.

Hypercalcemia

Estrogen administration may lead to severe hypercalcemia in women with breast cancer and bone metastases. If hypercalcemia occurs, use of the drug should be stopped and appropriate measures taken to reduce the serum calcium level.

Visual Abnormalities

Retinal vascular thrombosis has been reported in women receiving estrogens. Discontinue medication pending examination if there is sudden partial or complete loss of vision, or a sudden onset of proptosis, diplopia, or migraine. If examination reveals papilledema or retinal vascular lesions, estrogens should be permanently discontinued.

Addition of a Progestin When a Woman Has Not Had a Hysterectomy

Studies of the addition of a progestin for 10 or more days of a cycle of estrogen administration, or daily with estrogen in a continuous regimen, have reported a lowered incidence of endometrial hyperplasia than would be induced by estrogen treatment alone. Endometrial hyperplasia may be a precursor to endometrial cancer.

There are, however, possible risks that may be associated with the use of progestins with estrogens compared to estrogen-alone regimens. These include a possible increased risk of breast cancer.

Elevated Blood Pressure

In a small number of case reports, substantial increases in blood pressure have been attributed to idiosyncratic reactions to estrogens. In a large, randomized, placebo-controlled clinical trial, a generalized effect of estrogens on blood pressure was not seen.

Hypertriglyceridemia

In women with preexisting hypertriglyceridemia, estrogen therapy may be associated with elevations of plasma triglycerides leading to pancreatitis. Consider discontinuation of treatment if pancreatitis occurs.

Hepatic Impairment and/or Past History of Cholestatic Jaundice

Estrogens may be poorly metabolized in women with impaired liver function. For women with a history of cholestatic jaundice associated with past estrogen use or with pregnancy, caution should be exercised, and in the case of recurrence, medication should be discontinued.

Hypothyroidism

Estrogen administration leads to increased thyroid-binding globulin (TBG) levels. Women with normal thyroid function can compensate for the increased TBG by making more thyroid hormone, thus maintaining free T4 and T3 serum concentrations in the normal range. Women dependent on thyroid hormone replacement therapy who are also receiving estrogens may require increased doses of their thyroid replacement therapy. These women should have their thyroid function monitored in order to maintain their free thyroid hormone levels in an acceptable range.

Fluid Retention

Estrogens may cause some degree of fluid retention. Women with conditions that might be influenced by this factor, such as a cardiac or renal impairment, warrant careful observation when estrogen-alone is prescribed.

Hypocalcemia

Estrogen therapy should be used with caution in women with hypoparathyroidism as estrogen-induced hypocalcemia may occur.

Exacerbation of Endometriosis

A few cases of malignant transformation of residual endometrial implants have been reported in women treated post-hysterectomy with estrogen-alone therapy. For women known to have residual endometriosis post-hysterectomy, the addition of progestin should be considered.

Hereditary Angioedema

Exogenous estrogens may exacerbate symptoms of angioedema in women with hereditary angioedema.

Exacerbation of Other Conditions

Estrogen therapy may cause an exacerbation of asthma, diabetes mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and hepatic hemangiomas and should be used with caution in women with these conditions.

Laboratory Tests

Serum follicle stimulating hormone (FSH) and estradiol levels have not been shown to be useful in the management of moderate to severe vasomotor symptoms and moderate to severe symptoms of vulvar and vaginal atrophy.

Drug/Laboratory Test Interactions

1. Accelerated prothrombin time, partial thromboplastin time, and platelet aggregation time; increased platelet count; increased factors II, VII antigen, VIII antigen, VIII coagulant activity, IX, X, XII, VII-X complex, II-VII-X complex, and beta-thromboglobulin; decreased levels of anti-factor Xa and antithrombin III, decreased antithrombin III activity; increased levels of fibrinogen and fibrinogen activity; increased plasminogen antigen and activity. 2. Increased thyroid-binding globulin (TBG) levels leading to increased circulating total thyroid hormone levels, as measured by protein-bound iodine (PBI), T4 levels (by column or by radioimmunoassay) or T3 levels by radioimmunoassay. T3 resin uptake is decreased, reflecting the elevated TBG. Free T4 and free T3 concentrations are unaltered. Women on thyroid replacement therapy may require higher doses of thyroid hormone. 3. Other binding proteins may be elevated in serum, (for example, corticosteroid binding globulin [CBG], sex hormone binding globulin [SHBG]) leading to increased total circulating corticosteroids and sex steroids, respectively. Free hormone concentrations, such as testosterone and estradiol, may be decreased. Other plasma proteins may be increased (angiotensinogen/renin substrate, alpha-1-antitrypsin, ceruloplasmin). 4. Increased plasma high-density lipoprotein (HDL) and HDL2 cholesterol subfraction concentrations, reduced low-density lipoprotein (LDL) cholesterol concentration, and increased triglyceride levels. 5. Impaired glucose tolerance.

Drug Interactions

No drug-drug interaction studies have been conducted with Enjuvia.

Metabolic Interactions

In vitro and in vivo studies have shown that estrogens are metabolized partially by cytochrome P450 3A4 (CYP3A4). Therefore, inducers and inhibitors of CYP3A4 may affect estrogen drug metabolism. Inducers of CYP3A4, such as St. John’s wort (Hypericum perforatum) preparations, phenobarbital, carbamazepine, and rifampin, may reduce plasma concentrations of estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile. Inhibitors of CYP3A4, such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir, and grapefruit juice, may increase plasma concentrations of estrogens and may result in side effects.

Overdosage

Overdosage of estrogen may cause nausea and vomiting, breast tenderness, abdominal pain, drowsiness and fatigue, and withdrawal bleeding may occur in women. Treatment of overdose consists of discontinuation of Enjuvia therapy with institution of appropriate symptomatic care.

Enjuvia - Clinical Pharmacology

Mechanism of Action

Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol, at the receptor level.

The primary source of estrogen in normally cycling adult women is the ovarian follicle, which secretes 70 to 500 mcg of estradiol daily, depending on the phase of the menstrual cycle. After menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone in the peripheral tissues. Thus, estrone and the sulfate-conjugated form, estrone sulfate, are the most abundant circulating estrogens in postmenopausal women.

Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. To date, two estrogen receptors have been identified. These vary in proportion from tissue to tissue.

Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH), and FSH, through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones in postmenopausal women.

Pharmacodynamics

There are no pharmacodynamic data for Enjuvia.

Pharmacokinetics

Absorption

Synthetic conjugated estrogens, B are soluble in water and are well absorbed from the gastrointestinal tract after release from the drug formulation. Enjuvia tablets release synthetic conjugated estrogens, B slowly over a period of several hours. Table 3 and Table 4 summarize the mean pharmacokinetic parameters for unconjugated (free) and conjugated (total) estrogens following single administration of two 0.625 mg tablets to 21 healthy postmenopausal women under fasting conditions. The effect of food on the bioavailability of synthetic conjugated estrogens, B following administration of Enjuvia tablets has not been studied. However, the presence of food did not significantly affect the pharmacokinetics of a similar formulation of synthetic conjugated estrogens, B.

Table 3: Mean Pharmacokinetic Parameters of Unconjugated (Free) Estrogens Following a Single Dose of 2 x 0.625 mg Enjuvia Tablets Under Fasting Conditions*
Cmax
(pg/mL)
tmax
(hr)

(hr)
AUC0-48h
(pg•hr/mL)

Baseline-corrected estrone (% CV)

75.87 (39)

9.29 (25)

23.46 (59)

1601.59 (41)

Equilin (% CV)

41.94 (49)

8.38 (27)

15.09 (55)

707.21 (46)

Cmax = peak plasma concentration; tmax = time peak concentration occurs; t1/2 = apparent terminal-phase disposition half-life; AUC0-48h = total area under the concentration-time curve from time zero to time of last quantifiable concentration (48h); * Δ8,9 Dehydroestrone (free) levels were below the assay limit of quantitation; CV= Coefficient of Variance

Table 4: Mean Pharmacokinetic Parameters of Conjugated (Total) Estrogens Following a Single Dose of 2 x 0.625 mg Enjuvia Tablets Under Fasting Conditions
Cmax
(ng/mL)
tmax
(h)
t1/2
(h)
AUC0-48h
(ng•h/mL)

Baseline-corrected estrone (% CV)

3.74 (29)

8.00 (27)

14.26 (26)

62.03 (34)

Equilin (% CV)

3.69 (44)

8.05 (36)

11.28 (28)

58.25 (53)

Δ8,9 Dehydroestrone (% CV)

0.74 (32)

7.55 (37)

14.14 (26)

12.93 (39)

Cmax = peak plasma concentration; tmax = time peak concentration occurs; t1/2 = apparent terminal-phase disposition half-life; AUC0-48h = total area under the concentration-time curve from time zero to time of last quantifiable concentration (48h); CV= Coefficient of Variance

Distribution

The distribution of exogenous estrogens is similar to that of endogenous estrogens. Estrogens are widely distributed in the body and are generally found in higher concentrations in the sex hormone target organs. Estrogens circulate in the blood largely bound to SHBG and albumin.

Metabolism

Exogenous estrogens are metabolized in the same manner as endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium of metabolic interconversions. These transformations take place mainly in the liver. Estradiol is converted reversibly to estrone, and both can be converted to estriol, which is a major urinary metabolite. Estrogens also undergo enterohepatic recirculation via sulfate and glucuronide conjugation in the liver, biliary secretion of conjugates into the intestine, and hydrolysis in the intestine followed by reabsorption. In postmenopausal women, a significant portion of the circulating estrogens exist as sulfate conjugates, especially estrone sulfate, which serves as a circulating reservoir for the formation of more active estrogens.

Excretion

Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates. The mean (SD) apparent terminal elimination half-life (t½) of conjugated estrone is 14 (± 6) hours and conjugated equilin is 11 (± 6) hours.

Package/Label Display Panel

Enjuvia® (synthetic conjugated estrogens, B) Tablets 0.3 mg, 100s Label Text

  0.3 mg 100 Tablets

NDC 51285-406-02

Enjuvia®

(synthetic conjugated estrogens, B) Tablets

PHARMACIST: Dispense the Package Insert

provided separately to each patient.

Rx only

TEVA

TEVA WOMEN’S HEALTH

For the Consumer

Applies to conjugated estrogens: oral tablet

Other dosage forms:

  • intravenous powder for solution

Along with its needed effects, conjugated estrogens (the active ingredient contained in Enjuvia) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking conjugated estrogens:

More common
  • Bloating or swelling of the face, arms, hands, lower legs, or feet
  • cough
  • cramps
  • difficulty with swallowing
  • dizziness
  • fast heartbeat
  • heavy bleeding
  • hives, itching, or skin rash
  • itching of the vagina or genital area
  • normal menstrual bleeding occurring earlier, possibly lasting longer than expected
  • pain during sexual intercourse
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid weight gain
  • thick, white vaginal discharge with no odor or with a mild odor
  • tightness in the chest
  • tingling of the hands or feet
  • unusual tiredness or weakness
  • unusual weight gain or loss
Incidence not known
  • Acid or sour stomach
  • backache
  • belching
  • change in vaginal discharge
  • clear or bloody discharge from the nipple
  • confusion
  • decrease in the amount of urine
  • difficulty with speaking
  • dimpling of the breast skin
  • double vision
  • headache
  • heartburn
  • inability to move the arms, legs, or facial muscles
  • inability to speak
  • indigestion
  • inverted nipple
  • loss of appetite
  • lump in the breast or under the arm
  • noisy, rattling breathing
  • pain or feeling of pressure in the pelvis
  • pain, redness, or swelling in the arm or leg
  • persistent crusting or scaling of the nipple
  • redness or swelling of the breast
  • slow speech
  • sore on the skin of the breast that does not heal
  • stomach discomfort, upset, or pain
  • swelling of the abdominal or stomach area
  • swelling of the fingers, hands, feet, or lower legs
  • troubled breathing at rest
  • vaginal bleeding

Some side effects of conjugated estrogens may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • excess air or gas in the stomach or intestines
  • fear or nervousness
  • heartburn
  • increased clear or white vaginal discharge
  • indigestion
  • lack or loss of strength
  • loss of bladder control
  • nausea
  • passing gas
  • runny nose
  • sneezing
  • stuffy nose
  • vomiting
Less common
  • Back pain
  • increased appetite
Incidence not known
  • Breast pain, swelling, or tenderness
  • discouragement
  • enlarged breasts
  • feeling sad or empty
  • hair loss or thinning of the hair
  • irritability
  • lack of appetite
  • loss of interest or pleasure
  • sleepiness or unusual drowsiness
  • tiredness
  • trouble concentrating
  • trouble sleeping

For Healthcare Professionals

Applies to conjugated estrogens: injectable powder for injection, oral tablet, vaginal cream

Cardiovascular

-HRT is associated with a 1.3 to 3-fold increased relative risk of developing VTE, i.e., deep vein thrombosis or pulmonary embolism. This event is more likely to occur in the first year of using HRT.
-The use of estrogen-only and estrogen-progestin therapy is associated with an up to 1.5 fold increased relative risk of ischemic stroke.
-The risk of hemorrhagic stroke is not increased during use of HRT. This relative risk is not dependent on age or on duration of use, but as the baseline risk is strongly age-dependent, the overall risk of stroke in women who use HRT will increase with age.[Ref]

Common (1% to 10%): Hypertension, palpitation, vasodilation
Rare (less than 0.1%): Stroke
Postmarketing reports: Deep and superficial venous thrombosis, pulmonary embolism, thrombophlebitis, myocardial infarction, stroke[Ref]

Dermatologic

Common (1% to 10%): Acne, alopecia, hirsutism, pruritus, rash, skin discoloration, sweating, fungal dermatitis
Postmarketing reports: Chloasma or melasma (may persist when drug is discontinued), erythema multiforme, erythema nodosum, loss of scalp hair[Ref]

Gastrointestinal

Common (1% to 10%): Constipation, diarrhea, dyspepsia, eructation, flatulence, nausea
Uncommon (0.1% to 1%): Bloating, abdominal pain
Postmarketing reports: Vomiting, abdominal discomfort, abdominal distension[Ref]

Genitourinary

Common (1% to 10%): Pelvic pain, breast disorder, breast enlargement, breast neoplasm, breast pain, cervix disorder, dysmenorrhea, endometrial disorder, endometrial hyperplasia, leukorrhea, metrorrhagia, urinary tract infection, uterine fibroids enlarged, uterine spasm, abnormal uterine bleeding (breakthrough bleeding/spotting), vaginal dryness, vaginal hemorrhage, vaginal moniliasis, vaginitis
Uncommon (0.1% to 1%): Vaginal candidiasis, changes in menstrual flow, changes in cervical ectropion and secretion
Postmarketing reports: Increases in seize of uterine leiomyomata, change in cervical secretion, ovarian cancer, endometrial cancer, breast tenderness, breast discharge, galactorrhea, fibrocystic breast changes, breast cancer, gynecomastia in males[Ref]

Metabolic

Common (1% to 10%): Hyperlipidemia, weight gain, increased appetite
Very rare (less than 0.01%): Hypocalcemia
Postmarketing reports: Increase or decrease in weight, glucose intolerance, aggravation of porphyria, increased triglycerides[Ref]

Musculoskeletal

Common (1% to 10%): Back pain, arthralgia, leg cramps, myalgia, muscle spasm[Ref]

Nervous system

Common (1% to 10%): Headache, dizziness, paresthesia, migraine, hypertonia, insomnia, nervousness
Very rare (less than 0.01%): Exacerbation of chorea
Postmarketing reports: Exacerbation of epilepsy, dementia[Ref]

Other

Common (1% to 10%): Accidental injury, asthenia, chills, flu syndrome, pain, edema, peripheral edema, generalized edema, moniliasis
Postmarketing reports: Irritability[Ref]

Psychiatric

Common (1% to 10%): Depression, emotional liabilities, anxiety
Uncommon (0.1% to 1%): Changes in libido, mood disturbances[Ref]

Respiratory

Common (1% to 10%): Chest pain, bronchitis, increased cough, pharyngitis, rhinitis, sinusitis, upper respiratory tract infection
Postmarketing reports: Exacerbation of asthma[Ref]

Hepatic

Uncommon (0.1% to 1%): Gallbladder disease
Postmarketing reports: Cholestatic jaundice, pancreatitis, enlargement of hepatic hemangiomas, ischemic colitis[Ref]

Hypersensitivity

Uncommon (0.1% to 1%): Hypersensitivity
Rare (less than 0.1%): Anaphylactic/anaphylactoid reactions including urticaria and angioedema[Ref]

Ocular

Uncommon (0.1% to 1%): Intolerance to contact lenses, steepening of corneal curvature
Postmarketing reports: Retinal vascular thrombosis[Ref]

Oncologic

Rare (0.01% to 0.1%): Breast cancer, ovarian cancer, fibrocystic breast changes, growth potentiation of benign meningioma.
Very rare (less than 0.01%): Endometrial cancer, enlargement of hepatic hemangiomas[Ref]

Breast cancer:
-An up to 2-fold increased risk of having breast cancer diagnosed is reported in women taking combined estrogen-progestin therapy for more than 5 years.
-Any increased risk in users of estrogen-only therapy is substantially lower than that seen in users of estrogen-progestin combinations. The level of risk is dependent on the duration of use.

Endometrial Cancer:
-Endometrial cancer risk is about 5 in every 1000 women with a uterus not using HRT.
-In women with a uterus, use of estrogen-only HRT is not recommended because it increases the risk of endometrial cancer.
-Depending on the duration of estrogen-only use and estrogen dose, the increase in risk of endometrial cancer varied from between 5 and 55 extra cases diagnosed in every 1000 women between the ages of 50 and 65.
-Adding a progestin to estrogen-only therapy for at least 12 days per cycle can prevent this increased risk. In the Million Women Study the use of five years of combined HRT did not increase risk of endometrial cancer.

Ovarian cancer:
-Long-term use of estrogen-only and combined estrogen-progestin HRT has been associated with a slightly increased risk of ovarian cancer. In the Million Women Study 5 years of HRT resulted in 1 extra case per 2500 users.[Ref]

Some side effects of Enjuvia may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

(web3)