OGEN^®
estropipate tablets, USP

Close clinical surveillance of all women taking estrogens is important. Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding. There is no evidence that the use of "natural" estrogens result in a different endometrial risk profile than "synthetic" estrogens at equivalent estrogen doses. (See WARNINGS, Malignant neoplasms, Endometrial cancer.)

Estrogens with and without progestins should not be used for the prevention of cardiovascular disease. (See WARNINGS, Cardiovascular disorders.)

The Women's Health Initiative (WHI) study reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis in postmenopausal women (50 to 79 years of age) during 5 years of treatment with oral conjugated estrogens (CE 0.625 mg) combined with medroxyprogesterone acetate (MPA 2.5 mg) relative to placebo. (see CLINICAL PHARMACOLOGY, Clinical Studies.)

The Women's Health Initiative Memory Study (WHIMS), a substudy of WHI, reported increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with oral conjugated estrogens plus medroxyprogesterone acetate relative to placebo. It is unknown whether this finding applies to younger postmenopausal women or to women taking estrogen alone therapy. (See CLINICAL PHARMACOLOGY, Clinical Studies.)

OGEN (estropipate tablets), (formerly piperazine estrone sulfate), is a natural estrogenic substance prepared from purified crystalline estrone, solubilized as the sulfate and stabilized with piperazine. It is appreciably soluble in water and has almost no odor or taste — properties which are ideally suited for oral administration. The amount of piperazine in OGEN is not sufficient to exert a pharmacological action. Its addition ensures solubility, stability, and uniform potency of the estrone sulfate. Chemically estropipate, molecular weight: 436.56, is represented by estra-1,3,5(10)-trien-17-one,3-(sulfooxy)-, compound with piperazine (1:1). The structural formula may be represented as follows:

OGEN is available as tablets for oral administration containing either 0.75 mg (OGEN .625), 1.5 mg (OGEN 1.25), or 3 mg (OGEN 2.5) estropipate (Calculated as sodium estrone sulfate 0.625 mg, 1.25 mg, and 2.5 mg, respectively).

Each tablet contains: Colloidal silicon dioxide, dibasic potassium phosphate, hydrogenated vegetable oil wax, hydroxypropyl cellulose, lactose, magnesium stearate, microcrystalline cellulose, sodium starch glycolate and tromethamine.
OGEN .625 also contains: D&C Yellow No. 10 and FD&C Yellow No. 6.
OGEN 1.25 also contains: FD&C Yellow No. 6.
OGEN 2.5 also contains: FD&C Blue No. 2.

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 by 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 follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.

OGEN is indicated in the:

• Treatment of moderate to severe vasomotor symptoms associated with the menopause.
• Treatment of moderate to severe symptoms of vulval and vaginal atrophy associated with the menopause. When prescribing solely for the treatment of symptoms of vulvar and vaginal atrophy, topical vaginal products should be considered.
• Treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure.
• Prevention of postmenopausal osteoporosis. When prescribing solely for the prevention of postmenopausal osteoporosis, therapy should only be considered for women at significant risk of osteoporosis and for whom non-estrogen medications are not considered to be appropriate.
  The mainstays for decreasing the risk of postmenopausal osteoporosis are weight-bearing exercise, adequate calcium and vitamin D intake, and when indicated, pharmacologic therapy. Postmenopausal women require an average of 1500 mg/day of elemental calcium. Therefore, when not contraindicated, calcium supplementation may be helpful for women with suboptimal dietary intake. Vitamin D supplementation of 400–800 IU/day may also be required to ensure adequate daily intake in postmenopausal women.

OGEN should not be used in women with any of the following conditions:

• Undiagnosed abnormal genital bleeding.
• Known, suspected, or history of cancer of the breast.
• Known or suspected estrogen-dependent neoplasia.
• Active deep vein thrombosis, pulmonary embolism or history of these conditions.
• Active or recent (e.g., within the past year) arterial thromboembolic disease (e.g., stroke, myocardial infarction).
• Liver dysfunction or disease.
• OGEN should not be used in patients with known hypersensitivity to its ingredients.
• Known or suspected pregnancy. There is no indication for OGEN in pregnancy.

There appears to be little or no increased risk of birth defects in children born to women who have used estrogens and progestins from oral contraceptives inadvertently during early pregnancy. (See PRECAUTIONS.)

See BOXED WARNINGS

Estrogen and estrogen/progestin therapy have been associated with an increased risk of cardiovascular events such as myocardial infarction and stroke, as well as venous thrombosis and pulmonary embolism (venous thromboembolism or VTE). Should any of these occur or be suspected, estrogens should be discontinued immediately.

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

In the Women's Health Initiative Memory Study (WHIMS), 4,532 generally healthy postmenopausal women 65 years of age and older were studied, of whom 35% were 70 to 74 years of age and 18% were 75 or older. After an average follow-up of 4 years, 40 women being treated with CE/MPA (1.8%, n= 2,229) and 21 women in the placebo group (0.9%, n= 2,303) received diagnoses of probable dementia. The relative risk for CE/MPA versus placebo was 2.05 (95% confidence interval 1.21 – 3.48), and was similar for women with and without histories of menopausal hormone use before WHIMS. The absolute risk of probable dementia for CE/MPA versus placebo was 45 versus 22 cases per 10,000 women-years. It is unknown whether these findings apply to younger postmenopausal women. (See CLINICAL PHARMACOLOGY, Clinical Studies and PRECAUTIONS, Geriatric Use.)

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

Estrogen administration may lead to severe hypercalcemia in patients 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.

Retinal vascular thrombosis has been reported in patients 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.

Physicians are advised to discuss the PATIENT INFORMATION leaflet with patients for whom they prescribe OGEN.

Estrogen administration should be initiated at the lowest dose approved for the indication and then guided by clinical response rather than by serum hormone levels (e.g., estradiol, FSH).

• 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. Patients on thyroid replacement therapy may require higher doses of thyroid hormone.
• 3.Other binding proteins may be elevated in serum, (i.e., corticosteroid binding globulin (CBG), sex hormone-binding globulin (SHBG), leading to increased circulating corticosteroids and sex steroids, respectively. Free or biologically active hormone concentrations are unchanged. Other plasma proteins may be increased (angiotensinogen/renin substrate, alpha-l-antitrypsin, ceruloplasmin).
• 4.Increased plasma HDL and HDL₂ subfraction concentrations, reduced LDL cholesterol concentration, increased triglycerides levels.
• 5.Impaired glucose tolerance.
• 6.Reduced response to metyrapone test.
• 7.Reduced serum folate concentration.

Long-term continuous administration of estrogen, with and without progestin, in women with and without a uterus, has shown an increased risk of endometrial cancer, breast cancer, and ovarian cancer. (See BOXED WARNINGS, WARNINGS, and PRECAUTIONS.)

Long-term continuous administration of natural and synthetic estrogens in certain animal species increases the frequency of carcinomas of the breast, uterus, cervix, vagina, testis, and liver.

OGEN should not be used during pregnancy. (See CONTRAINDICATIONS.)

Estrogen administration to nursing mothers has been shown to decrease the quantity and quality of the milk. Detectable amounts of estrogens have been identified in the milk of mothers receiving this drug. Caution should be exercised when OGEN is administered to a nursing woman.

In the Women's Health Initiative Memory Study, including 4,532 women 65 years of age and older, followed for an average of 4 years, 82% (n= 3,729) were 65 to 74 while 18% (n= 803) were 75 and over. Most women (80%) had no prior hormone therapy use. Women treated with conjugated estrogens plus medroxyprogesterone acetate were reported to have a two-fold increase in the risk of developing probable dementia. Alzheimer's disease was the most common classification of probable dementia in both the conjugated estrogens plus medroxyprogesterone acetate group and the placebo group. Ninety percent of the cases of probable dementia occurred in the 54% of women that were older than 70. (See WARNINGS, Dementia.)

See BOXED WARNINGS, WARNINGS and PRECAUTIONS.

The following additional adverse reactions have been reported with estrogens and/or progestin therapy.

Changes in vaginal bleeding pattern and 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; ovarian cancer; endometrial hyperplasia; endometrial cancer.

Tenderness, enlargement, pain, nipple discharge, galactorrhea; fibrocystic breast changes; breast cancer.

Deep and superficial venous thrombosis; pulmonary embolism; thrombophlebitis; myocardial infarction; stroke; increase in blood pressure.

Nausea, vomiting; abdominal cramps, bloating; cholestatic jaundice; increased incidence of gallbladder disease; pancreatitis; enlargement of hepatic hemangiomas.

Chloasma or melasma that may persist when drug is discontinued; erythema multiforme; erythema nodosum; hemorrhagic eruption; loss of scalp hair; hirsutism; pruritus, rash.

Retinal vascular thrombosis; steepening of corneal curvature; intolerance to contact lenses.

Headache, migraine, dizziness; mental depression; chorea; nervousness; mood disturbances; irritability; exacerbation of epilepsy; dementia.

Increase or decrease in weight; reduced carbohydrate tolerance; aggravation of porphyria; edema; arthralgias; leg cramps; urticaria; angioedema; anaphylactoid/anaphylactic reactions; hypocalcemia; exacerbation of asthma; changes in libido; triglycerides.

Serious ill effects have not been reported following acute ingestion of large doses of estrogen-containing oral contraceptives by young children. Overdosage of estrogen may cause nausea and vomiting, and withdrawal bleeding may occur in females.

When estrogen is prescribed for a woman with a uterus, progestin should also be initiated to reduce the risk of endometrial cancer. A woman without a uterus does not need progestin. Use of estrogen, alone or in combination with a progestin, should be with the lowest effective dose and for the shortest duration consistent with treatment goals and risks for the individual woman. Patients should be reevaluated periodically as clinically appropriate (e.g., 3-month to 6-month intervals) to determine if treatment is still necessary (See BOXED WARNINGS and WARNINGS.) For women who have a uterus, adequate diagnostic measures, such as endometrial sampling, when indicated, should be undertaken to rule out malignancy in cases of undiagnosed persistent or recurring abnormal vaginal bleeding.

• For treatment of moderate to severe vasomotor symptoms, vulval and vaginal atrophy associated with the menopause, the lowest dose and regimen that will control symptoms should be chosen and medication should be discontinued as promptly as possible. Attempts to discontinue or taper medication should be made at 3month to 6-month intervals. Usual dosage ranges:
  Vasomotor symptoms—One OGEN .625 (0.75 mg estropipate) tablet to two OGEN 2.5 (3 mg estropipate) tablets per day. The lowest dose that will control symptoms should be chosen. If the patient has not menstruated within the last two months or more, cyclic administration is started arbitrarily. If the patient is menstruating, cyclic administration is started on day 5 of bleeding.
  Vulval and vaginal atrophy—One OGEN .625 (0.75 mg estropipate) tablet to two OGEN 2.5 (3 mg estropipate) tablets daily, depending upon the tissue response of the individual patient. The lowest dose that will control symptoms should be chosen. Administer cyclically.
• For treatment of female hypoestrogenism due to hypogonadism, castration, or primary ovarian failure. Usual dosage ranges:
  Female hypogonadism—A daily dose of one OGEN 1.25 (1.5 mg estropipate) tablet to three OGEN 2.5 (3 mg estropipate) tablets may be given for the first three weeks of a theoretical cycle, followed by a rest period of eight to ten days. The lowest dose that will control symptoms should be chosen. If bleeding does not occur by the end of this period, the same dosage schedule is repeated. The number of courses of estrogen therapy necessary to produce bleeding may vary depending on the responsiveness of the endometrium. If satisfactory withdrawal bleeding does not occur, an oral progestogen may be given in addition to estrogen during the third week of the cycle.
  Female castration or primary ovarian failure—A daily dose of one OGEN 1.25 (1.5 mg estropipate) tablet to three OGEN 2.5 (3 mg estropipate) tablets may be given for the first three weeks of a theoretical cycle, followed by a rest period of eight to ten days. Adjust dosage upward or downward according to severity of symptoms and response of the patient. For maintenance, adjust dosage to lowest level that will provide effective control.
  Treated patients with an intact uterus should be monitored closely for signs of endometrial cancer and appropriate diagnostic measures should be taken to rule out malignancy in the event of persistent or recurring abnormal vaginal bleeding.
• For prevention of osteoporosis. A daily dose of one OGEN .625 (0.75 mg estropipate) tablet for 25 days of a 31-day cycle per month.

OGEN (estropipate tablets, USP) is supplied as OGEN .625 (0.75 mg estropipate; calculated as sodium estrone sulfate 0.625 mg), yellow, scored tablets, imprinted U 3772, NDC 0009-3772-01; OGEN 1.25 (1.5 mg estropipate; calculated as sodium estrone sulfate 1.25 mg), peach-colored, scored tablets, imprinted U 3773, NDC 0009-3773-01; and OGEN 2.5 (3 mg estropipate; calculated as sodium estrone sulfate 2.5 mg), blue, scored tablets, imprinted U 3774, NDC 0009-3774-01. Tablets of all three dosage levels are standardized to provide uniform estrone activity and are scored to provide dosage flexibility. All tablet sizes of OGEN are available in bottles of 100.

Recommended storage: Store below 77°F (25°C)

Read this PATIENT INFORMATION before you start taking OGEN and read what you get each time you refill OGEN. There may be new information. This information does not take the place of talking to your health care provider about your medical condition or your treatment.

• Estrogens increase the chances of getting cancer of the uterus.

Report any unusual vaginal bleeding right away while you are taking estrogens. Vaginal bleeding after menopause may be a warning sign of cancer of the uterine (womb). Your health care provider should check any unusual vaginal bleeding to find out the cause.

• Do not use estrogens with or without progestins to prevent heart disease, heart attacks or strokes.

Using estrogens with or without progestins may increase your chances of getting heart attacks, strokes, breast cancer and blood clots. You and your health care provider should talk regularly about whether you still need treatment with OGEN.