Prempro (conjugated estrogens and medroxyprogesterone acetate) - Dosing, PA Forms & Info (2026)
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    2. Premphase - Conjugated Estrogens And Medroxyprogesterone Acetate

    Get your patient on Premphase - Conjugated Estrogens And Medroxyprogesterone Acetate (Conjugated Estrogens And Medroxyprogesterone Acetate)

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    Premphase - Conjugated Estrogens And Medroxyprogesterone Acetate prescribing information

    • Boxed warning
    • Indications & usage
    • Dosage & administration
    • Dosage forms & strengths
    • Pregnancy & lactation
    • Contraindications
    • Warnings & precautions
    • Adverse reactions
    • Drug interactions
    • Description
    • Pharmacology
    • Nonclinical toxicology
    • Clinical studies
    • How supplied/storage & handling
    • Mechanism of action
    • Data source
    • Boxed warning
    • Indications & usage
    • Dosage & administration
    • Dosage forms & strengths
    • Pregnancy & lactation
    • Contraindications
    • Warnings & precautions
    • Adverse reactions
    • Drug interactions
    • Description
    • Pharmacology
    • Nonclinical toxicology
    • Clinical studies
    • How supplied/storage & handling
    • Mechanism of action
    • Data source
    Prescribing Information
    Boxed Warning

    WARNING: CARDIOVASCULAR DISORDERS, BREAST CANCER, ENDOMETRIAL CANCER and PROBABLE DEMENTIA

    Estrogen Plus Progestin Therapy

    Cardiovascular Disorders and Probable Dementia

    Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1 , 5.3) , and Clinical Studies (14.6 , 14.7) ] .

    The Women's Health Initiative (WHI) estrogen plus progestin substudy reported an increased risk of deep vein thrombosis (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 estrogen (CE) (0.625 mg) combined with medroxyprogesterone acetate (MPA) (2.5 mg), relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.6) ] .

    The WHI Memory Study (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 CE (0.625 mg) combined with MPA (2.5 mg), relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see Warnings and Precautions (5.3) , Use in Specific Populations (8.5) , and Clinical Studies (14.7) ] .

    Breast Cancer

    The WHI estrogen plus progestin substudy also demonstrated an increased risk of invasive breast cancer [see Warnings and Precautions (5.2) , and Clinical Studies (14.6) ] .

    In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and MPA and other combinations and dosage forms of estrogens and 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.

    Estrogen-Alone Therapy

    Endometrial 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 undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding [see Warnings and Precautions (5.2) ] .

    Cardiovascular Disorders and Probable Dementia

    Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1 , 5.3) , and Clinical Studies (14.6 , 14.7) ] .

    The WHI estrogen-alone substudy reported increased risks of stroke and DVT in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral CE (0.625 mg)-alone, relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.6) ] .

    The WHIMS estrogen-alone ancillary study of 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 CE (0.625 mg)-alone, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see Warnings and Precautions (5.3) , Use in Specific Populations (8.5) , and Clinical Studies (14.7) ] .

    In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and other dosage forms of estrogens.

    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.

    Indications & Usage

    INDICATIONS AND USAGE

    Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause

    Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause

    Prevention of Postmenopausal Osteoporosis

    Dosage & Administration

    DOSAGE AND ADMINISTRATION

    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. Postmenopausal women should be re-evaluated periodically as clinically appropriate to determine if treatment is still necessary.

    Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause

    PREMPRO therapy consists of a single tablet to be taken orally once daily.

    PREMPHASE therapy consists of two separate tablets: one maroon 0.625 mg Premarin [conjugated estrogens (CE)] tablet taken daily on days 1 through 14 and one light-blue tablet containing 0.625 mg CE and 5 mg of medroxyprogesterone acetate (MPA) taken on days 15 through 28.

    Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause

    PREMPRO therapy consists of a single tablet to be taken orally once daily.

    PREMPHASE therapy consists of two separate tablets: one maroon 0.625 mg CE tablet taken daily on days 1 through 14 and one light-blue tablet containing 0.625 mg CE and 5 mg MPA taken on days 15 through 28.

    When prescribing solely for the treatment of moderate to severe vulvar and vaginal atrophy, topical vaginal products should be considered.

    Prevention of Postmenopausal Osteoporosis

    PREMPRO therapy consists of a single tablet to be taken orally once daily.

    PREMPHASE therapy consists of two separate tablets: one maroon 0.625 mg CE tablet taken daily on days 1 through 14 and one light-blue tablet containing 0.625 mg CE and 5 mg of MPA taken on days 15 through 28.

    When prescribing solely for the prevention of postmenopausal osteoporosis, therapy should only be considered for women at significant risk of osteoporosis and non-estrogen medications should be carefully considered.

    Dosage Forms & Strengths

    DOSAGE FORMS AND STRENGTHS

    PREMPRO (conjugated estrogens/medroxyprogesterone acetate tablets)

    Tablet Strength

    Tablet Shape/Color

    Imprint

    0.3 mg CE plus 1.5 mg MPA

    oval/cream

    PREMPRO
    0.3/1.5

    0.45 mg CE plus 1.5 mg MPA

    oval/gold

    PREMPRO
    0.45/1.5

    0.625 mg CE plus 2.5 mg MPA

    oval/peach

    PREMPRO
    0.625/2.5

    0.625 mg CE plus 5 mg MPA

    oval/light blue

    PREMPRO
    0.625/5

    PREMPHASE (conjugated estrogens/medroxyprogesterone acetate tablets)

    Tablet Strength

    Tablet Shape/Color

    Imprint

    0.625 mg CE

    oval/maroon (14 tablets)

    PREMARIN
    0.625

    0.625 mg CE plus 5 mg MPA

    oval/light-blue (14 tablets)

    PREMPRO
    0.625/5

    Pregnancy & Lactation

    USE IN SPECIFIC POPULATIONS

    • Lactation: Estrogen administration to lactating women has been shown to decrease the quantity and quality of breast milk (8.2 )
    • Geriatric Use: An increased risk of probable dementia in women over 65 years of age was reported in the Women's Health Initiative Memory ancillary studies of the Women's Health Initiative (5.3 , 8.5 )

    Pregnancy

    Risk Summary

    PREMPRO and PREMPHASE are not indicated for use during pregnancy.

    There are no data with the use of PREMPRO and PREMPHASE in pregnant women; however, epidemiologic studies and meta-analyses have not found an increased risk of genital or nongenital birth defects (including cardiac anomalies and limb-reduction defects) following exposure to combined hormonal contraceptives (estrogen and progestins) before conception or during early pregnancy.

    In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

    Lactation

    Risk Summary

    Estrogens and progestins and metabolites are present in human milk. These hormones can reduce milk production in breast-feeding women. This reduction can occur at any time but is less likely to occur once breast-feeding is well established. The developmental and health benefits of breast-feeding should be considered along with the mother’s clinical need for PREMPRO or PREMPHASE and any potential adverse effects on the breast-fed child from PREMPRO or PREMPHASE or from the underlying maternal condition.

    Pediatric Use

    PREMPRO and PREMPHASE are not indicated in children. Clinical studies have not been conducted in the pediatric population.

    Geriatric Use

    There have not been sufficient numbers of geriatric women involved in clinical studies utilizing PREMPRO or PREMPHASE to determine whether those over 65 years of age differ from younger subjects in their response to PREMPRO or PREMPHASE.

    The Women's Health Initiative Study

    In the WHI estrogen plus progestin substudy (daily CE [0.625 mg] plus MPA [2.5 mg] versus placebo), there was a higher relative risk of nonfatal stroke and invasive breast cancer in women greater than 65 years of age [see Clinical Studies (14.6) ] .

    In the WHI estrogen-alone substudy (daily CE [0.625 mg]-alone versus placebo), there was a higher relative risk of stroke in women greater than 65 years of age [see Clinical Studies (14.6) ] .

    The Women's Health Initiative Memory Study

    In the WHIMS ancillary studies of postmenopausal women 65 to 79 years of age, there was an increased risk of developing probable dementia in women receiving estrogen plus progestin or estrogen-alone when compared to placebo [see Warnings and Precautions (5.3) , and Clinical Studies (14.7) ] .

    Since both ancillary studies were conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women 8 [see Warnings and Precautions (5.3) , and Clinical Studies (14.7) ] .

    Renal Impairment

    The effects of renal impairment on the pharmacokinetics of PREMPRO or PREMPHASE have not been studied.

    Hepatic Impairment

    The effects of hepatic impairment on the pharmacokinetics of PREMPRO or PREMPHASE have not been studied.

    Contraindications

    CONTRAINDICATIONS

    PREMPRO and PREMPHASE are contraindicated in women with any of the following conditions:

    • Undiagnosed abnormal genital bleeding [see Warnings and Precautions (5.2) ]
    • Breast cancer or a history of breast cancer [see Warnings and Precautions (5.2) ]
    • Estrogen-dependent neoplasia [see Warnings and Precautions (5.2) ]
    • Active DVT, PE, or a history of these conditions [see Warnings and Precautions (5.1) ]
    • Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions [see Warnings and Precautions (5.1) ]
    • Known anaphylactic reaction or angioedema with PREMPRO/PREMPHASE [see Warnings and Precautions (5.15 , 5.16 )]
    • Hepatic impairment or disease [see Warnings and Precautions (5.10) ]
    • Protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders
    Warnings & Precautions

    WARNINGS AND PRECAUTIONS

    • Estrogens increase the risk of gallbladder disease (5.4 )
    • Discontinue estrogen if severe hypercalcemia, loss of vision, severe hypertriglyceridemia or cholestatic jaundice occurs (5.5 , 5.6 , 5.9 , 5.10 )
    • Monitor thyroid function in women on thyroid replacement therapy (5.11 , 5.19 )

    Cardiovascular Disorders

    An increased risk of PE, DVT, stroke and MI has been reported with estrogen plus progestin therapy. An increased risk of stroke and DVT has been reported with estrogen-alone 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 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) [see Clinical Studies (14.6) ] . 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.

    In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily 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 [see Clinical Studies (14.6) ] . 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 women-years). 1

    Coronary Heart Disease

    In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of coronary heart disease (CHD) events (defined as nonfatal MI, silent MI, or CHD death) 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 (14.6) ] .

    In the WHI estrogen-alone substudy, no overall effect on CHD events was reported in women receiving estrogen-alone compared to placebo 2 [see Clinical Studies (14.6) ] .

    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). 1

    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 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 plus MPA group and the placebo group in HERS, HERS II, and overall.

    Venous Thromboembolism (VTE)

    In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE (DVT and PE) was reported in women receiving daily 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 persisted 3 [see Clinical Studies (14.6) ] . Should a VTE occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.

    In the WHI estrogen-alone substudy, the risk of VTE 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 years 4 [see Clinical Studies (14.6) ] . Should a VTE occur or be suspected, estrogen-alone 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

    Breast Cancer

    The WHI substudy of daily CE (0.625 mg)-alone provided information about breast cancer in estrogen-alone users. In the WHI estrogen-alone substudy, after an average follow-up of 7.1 years, daily CE (0.625 mg)-alone was not associated with an increased risk of invasive breast cancer [relative risk (RR) 0.80] 5 [see Clinical Studies (14.6)] .

    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% 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 placebo. 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 6 [see Clinical Studies (14.6) ] .

    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. One large meta-analysis of prospective cohort studies reported increased risks that were dependent upon duration of use and could last up to > 10 years after discontinuation of estrogen plus progestin therapy and estrogen-alone therapy. Extension of the WHI trials also demonstrated increased breast cancer risk associated with estrogen plus progestin therapy. Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with estrogen plus progestin therapy as compared to the risk with 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.

    Endometrial Cancer

    Endometrial hyperplasia (a possible precursor of endometrial cancer) has been reported to occur at a rate of approximately 1% or less with PREMPRO or PREMPHASE.

    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 to be 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 using 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 estrogen therapy in postmenopausal women has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer.

    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% confidence interval (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

    A meta-analysis of 17 prospective and 35 retrospective epidemiology studies found that women who used hormonal therapy for menopausal symptoms had an increased risk for ovarian cancer. The primary analysis, using case-control comparisons, included 12,110 cancer cases from the 17 prospective studies. The relative risks associated with current use of hormonal therapy was 1.41 (95% CI 1.32 to 1.50); there was no difference in the risk estimates by duration of the exposure (less than 5 years [median of 3 years] vs. greater than 5 years [median of 10 years] of use before the cancer diagnosis). The relative risk associated with combined current and recent use (discontinued use within 5 years before cancer diagnosis) was 1.37 (95% CI 1.27–1.48), and the elevated risk was significant for both estrogen-alone and estrogen plus progestin products. The exact duration of hormone therapy use associated with an increased risk of ovarian cancer, however, is unknown.

    Probable Dementia

    In the WHIMS estrogen plus progestin ancillary study of WHI, 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 4 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% 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-years 8 [see Use in Specific Populations (8.5) , and Clinical Studies (14.7) ] .

    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% 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-years 8 [see Use in Specific Populations (8.5) , and Clinical Studies (14.7) ] .

    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% CI, 1.19–2.60). Since both substudies were conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women 8 [see Use in Specific Populations (8.5) , and Clinical Studies (14.7) ] .

    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 an 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 estrogen therapy on blood pressure was not seen.

    Exacerbation of Hypertriglyceridemia

    In women with pre-existing 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.

    Exacerbation of 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 T 4 and T 3 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 plus progestins may cause some degree of fluid retention. Women with conditions that might be influenced by this factor, such as a cardiac or renal dysfunction, warrant careful observation when estrogens plus progestins are 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.

    Anaphylactic Reaction and Angioedema

    Cases of anaphylaxis, which developed within minutes to hours after taking PREMPRO or PREMPHASE and require emergency medical management, have been reported in the postmarketing setting. Skin (hives, pruritis, swollen lips-tongue-face) and either respiratory tract (respiratory compromise) or gastrointestinal tract (abdominal pain, vomiting) involvement has been noted.

    Angioedema involving the tongue, larynx, face, hands, and feet requiring medical intervention has occurred postmarketing in patients taking PREMPRO or PREMPHASE. If angioedema involves the tongue, glottis, or larynx, airway obstruction may occur. Patients who develop an anaphylactic reaction with or without angioedema after treatment with PREMPRO or PREMPHASE should not receive PREMPRO or PREMPHASE again.

    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

    • 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.
    • Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid hormone, as measured by protein-bound iodine (PBI), T 4 levels (by column or by radioimmunoassay), or T 3 levels by radioimmunoassay. T 3 resin uptake is decreased, reflecting the elevated TBG. Free T 4 and free T 3 concentrations are unaltered. Women on thyroid replacement therapy may require higher doses of thyroid hormone.
    • 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).
    • Increased plasma high-density lipoprotein (HDL) and HDL 2 cholesterol subfraction, reduced low-density lipoprotein (LDL) cholesterol, increased triglyceride levels.
    • Impaired glucose tolerance.
    Adverse Reactions

    ADVERSE REACTIONS

    The following serious adverse reactions are discussed elsewhere in the labeling:

    • Cardiovascular Disorders [see Boxed Warning , Warnings and Precautions (5.1) ]
    • Malignant Neoplasms [see Boxed Warning , Warnings and Precautions (5.2) ]

    Clinical Trials Experience

    Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trial of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

    In a 1-year clinical trial that included 678 postmenopausal women treated with PREMPRO and 351 postmenopausal women treated with PREMPHASE, the following adverse reactions occurred at a rate ≥ 1%, see Table 1 .

    Table 1: Treatment-Related Adverse Reactions at a Frequency ≥1%

    Body System

    PREMPRO
    0.625 mg/2.5 mg
    continuous

    PREMPRO
    0.625 mg/5 mg
    continuous

    PREMPHASE
    0.625 mg/5 mg
    sequential

    Adverse event

    (n = 340)

    (n = 338)

    (n = 351)

    Body As A Whole

    Abdominal pain

    35 (10%)

    51 (15%)

    58 (17%)

    Asthenia

    13 (4%)

    18 (5%)

    21 (6%)

    Back pain

    19 (6%)

    16 (5%)

    23 (7%)

    Chest pain

    5 (1%)

    4 (1%)

    4 (1%)

    Flu syndrome

    1 (<1%)

    1 (<1%)

    4 (1%)

    Generalized edema

    12 (4%)

    12 (4%)

    8 (2%)

    Headache

    64 (19%)

    52 (15%)

    66 (19%)

    Infection

    2 (<1%)

    4 (1)%

    0

    Moniliasis

    4 (1%)

    3 (<1%)

    4 (1%)

    Pain

    12 (4%)

    14 (4%)

    15 (4%)

    Pelvic pain

    11 (3%)

    13 (4%)

    16 (5%)

    Cardiovascular System

    Hypertension

    7 (2%)

    7 (2%)

    6 (2%)

    Migraine

    6 (2%)

    8 (2%)

    7 (2%)

    Palpitation

    2 (<1%)

    3 (<1%)

    4 (1%)

    Vasodilatation

    2 (<1%)

    7 (2%)

    2 (<1%)

    Digestive System

    Diarrhea

    4 (1%)

    3 (<1%)

    7 (2%)

    Dyspepsia

    5 (1%)

    5 (1%)

    7 (2%)

    Eructation

    0

    2 (<1%)

    4 (1%)

    Flatulence

    25 (7%)

    27 (8%)

    24 (7%)

    Increased appetite

    1 (<1%)

    5 (1%)

    5 (1%)

    Nausea

    26 (8%)

    19 (6%)

    26 (7%)

    Metabolic and Nutritional

    Edema

    5 (1%)

    6 (2%)

    3 (<1%)

    Glucose tolerance
    decreased

    2 (<1%)

    5 (1%)

    4 (1%)

    Peripheral edema

    11 (3%)

    10 (3%)

    11 (3%)

    Weight gain

    9 (3%)

    10 (3%)

    11 (3%)

    Musculoskeletal System

    Arthralgia

    6 (2%)

    2 (<1%)

    7 (2%)

    Leg cramps

    8 (2%)

    11 (3%)

    12 (3%)

    Nervous System

    Depression

    14 (4%)

    26 (8%)

    29 (8%)

    Dizziness

    9 (3%)

    8 (2%)

    7 (2%)

    Emotional lability

    5 (1%)

    5 (1%)

    6 (2%)

    Hypertonia

    4 (1%)

    4 (1%)

    7 (2%)

    Insomnia

    7 (2%)

    6 (2%)

    4 (1%)

    Nervousness

    4 (1%)

    9 (3%)

    6 (2%)

    Skin and Appendages

    Acne

    1 (<1%)

    5 (1%)

    4 (1%)

    Alopecia

    3 (<1%)

    4 (1%)

    0

    Dry skin

    2 (<1%)

    3 (<1%)

    4 (1%)

    Pruritus

    20 (6%)

    18 (5%)

    13 (4%)

    Rash

    8 (2%)

    6 (2%)

    7 (2%)

    Sweating

    2 (<1%)

    4 (1%)

    2 (<1%)

    Urogenital System

    Breast engorgement

    5 (1%)

    5 (1%)

    0

    Breast enlargement

    14 (4%)

    14 (4%)

    14 (4%)

    Breast neoplasm

    2 (<1%)

    2 (<1%)

    4 (1%)

    Breast pain

    110 (32%)

    123 (36%)

    109 (31%)

    Cervix disorder

    10 (3%)

    6 (2%)

    10 (3%)

    Dysmenorrhea

    26 (8%)

    18 (5%)

    44 (13%)

    Leukorrhea

    19 (6%)

    13 (4%)

    29 (8%)

    Menstrual disorder

    7 (2%)

    1 (<1%)

    5 (1%)

    Menorrhagia

    0

    1 (<1%)

    5 (1%)

    Metrorrhagia

    13 (4%)

    5 (1%)

    7 (1%)

    Papanicolaou smear
    suspicious

    5 (1%)

    0

    8 (2%)

    Urinary incontinence

    4 (1%)

    2 (<1%)

    1 (<1%)

    Uterine spasm

    7 (2%)

    4 (1%)

    7 (2%)

    Vaginal hemorrhage

    5 (1%)

    3 (<1%)

    8 (2%)

    Vaginal moniliasis

    5 (1%)

    6 (2%)

    7 (2%)

    Vaginitis

    13 (4%)

    13 (4%)

    10 (3%)

    In addition, phargyngitis and sinusitis were reported as two of the more frequent adverse events (>5%) in the PREMPRO clinical study. For pharyngitis, of the 121 events, six events were considered by the investigator causally related to study drug. For sinusitis, of the 73 events, one event was considered as casually related to study drug.

    During the first year of a 2-year clinical trial with postmenopausal women between 40 and 65 years of age (88% Caucasian), 989 postmenopausal women received continuous regimens of PREMPRO, and 332 received placebo tablets. Table 2 summarizes adverse reactions that occurred at a rate ≥ 1% in at least 1 treatment group.

    Table 2: All Treatment-Related Adverse Reactions at a Frequency of ≥1%

    Body System
    Adverse event

    PREMPRO
    0.625/2.5
    continuous
    (N=331)

    PREMPRO
    0.45/1.5
    continuous
    (N=331)

    PREMPRO
    0.3/1.5
    continuous
    (N=327)

    PLACEBO
    daily
    (N=332)

    Any adverse event

    214 (65)

    208 (63)

    188 (57)

    164 (49)

    Body as a Whole

    Abdominal pain

    38 (11)

    33 (10)

    24 (7)

    21 (6)

    Asthenia

    11 (3)

    11 (3)

    12 (4)

    3 (1)

    Back pain

    12 (4)

    12 (4)

    8 (2)

    4 (1)

    Chest pain

    4 (1)

    2 (1)

    1 (0)

    2 (1)

    Generalized edema

    7 (2)

    5 (2)

    6 (2)

    8 (2)

    Headache

    45 (14)

    45 (14)

    57 (17)

    46 (14)

    Moniliasis

    3 (1)

    6 (2)

    4 (1)

    1 (0)

    Pain

    9 (3)

    10 (3)

    17 (5)

    14 (4)

    Pelvic pain

    9 (3)

    7 (2)

    5 (2)

    4 (1)

    Cardiovascular System

    Hypertension

    2 (1)

    3 (1)

    1 (0)

    5 (2)

    Migraine

    11 (3)

    8 (2)

    5 (2)

    3 (1)

    Palpitation

    1 (0)

    1 (0)

    2 (1)

    4 (1)

    Vasodilatation

    0

    3 (1)

    1 (0)

    5 (2)

    Digestive System

    Constipation

    5 (2)

    7 (2)

    6 (2)

    3 (1)

    Diarrhea

    5 (2)

    2 (1)

    6 (2)

    8 (2)

    Dyspepsia

    10 (3)

    9 (3)

    6 (2)

    14 (4)

    Flatulence

    16 (5)

    18 (5)

    13 (4)

    8 (2)

    Increased appetite

    6 (2)

    2 (1)

    0

    2 (1)

    Nausea

    13 (4)

    13 (4)

    16 (5)

    16 (5)

    Metabolic and nutritional

    Peripheral edema

    7 (2)

    8 (2)

    4 (1)

    3 (1)

    Weight gain

    9 (3)

    8 (2)

    6 (2)

    14 (4)

    Musculoskeletal System

    Arthralgia

    2 (1)

    3 (1)

    3 (1)

    5 (2)

    Leg cramps

    13 (4)

    7 (2)

    10 (3)

    4 (1)

    Nervous System

    Anxiety

    5 (2)

    4 (1)

    1 (0)

    4 (1)

    Depression

    23 (7)

    11 (3)

    11 (3)

    17 (5)

    Dizziness

    3 (1)

    8 (2)

    6 (2)

    5 (2)

    Emotional lability

    10 (3)

    10 (3)

    9 (3)

    8 (2)

    Insomnia

    8 (2)

    7 (2)

    9 (3)

    14 (4)

    Nervousness

    6 (2)

    3 (1)

    4 (1)

    6 (2)

    Skin and Appendages

    Acne

    7 (2)

    3 (1)

    0

    3 (1)

    Alopecia

    1 (0)

    6 (2)

    4 (1)

    2 (1)

    Pruritus

    8 (2)

    10 (3)

    9 (3)

    3 (1)

    Rash

    0

    6 (2)

    4 (1)

    2 (1)

    Skin discoloration

    5 (2)

    1 (0)

    3 (1)

    1 (0)

    Sweating

    3 (1)

    1 (0)

    0

    4 (1)

    Urogenital System

    Breast disorder

    7 (2)

    6 (2)

    5 (2)

    6 (2)

    Breast enlargement

    18 (5)

    9 (3)

    5 (2)

    3 (1)

    Breast neoplasm

    8 (2)

    7 (2)

    5 (2)

    7 (2)

    Breast pain

    87 (26)

    66 (20)

    41 (13)

    26 (8)

    Cervix disorder

    7 (2)

    2 (1)

    2 (1)

    0

    Dysmenorrhea

    14 (4)

    18 (5)

    9 (3)

    2 (1)

    Hematuria

    4 (1)

    3 (1)

    1 (0)

    2 (1)

    Leukorrhea

    7 (2)

    14 (4)

    9 (3)

    6 (2)

    Metrorrhagia

    7 (2)

    14 (4)

    4 (1)

    1 (0)

    Urinary tract infection

    0

    1 (0)

    1 (0)

    4 (1)

    Uterine spasm

    13 (4)

    11 (3)

    7 (2)

    2 (1)

    Vaginal dryness

    2 (1)

    1 (0)

    0

    6 (2)

    Vaginal hemorrhage

    18 (5)

    14 (4)

    7 (2)

    0

    Vaginal moniliasis

    13 (4)

    11 (3)

    8 (2)

    5 (2)

    Vaginitis

    6 (2)

    8 (2)

    7 (2)

    1 (0)

    In addition, the following events were considered as related to the study drug with an incidence less than 1%, including accidental injury, infection, myalgia, cough increased, rhinitis, sinusitis, and upper respiratory infection.

    Postmarketing Experience

    The following adverse reactions have been identified during post-approval use of PREMPRO or PREMPHASE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

    Genitourinary System

    Abnormal uterine bleeding, dysmenorrhea or pelvic pain, increase in size of uterine leiomyomata, vaginitis, vaginal candidiasis, amenorrhea, changes in cervical secretion, ovarian cancer, endometrial hyperplasia, endometrial cancer.

    Breasts

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

    Cardiovascular

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

    Gastrointestinal

    Nausea, vomiting, abdominal pain, bloating, cholestatic jaundice, increased incidence of gallbladder disease, pancreatitis, changes in appetite, ischemic colitis.

    Skin

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

    Eyes

    Retinal vascular thrombosis, intolerance of contact lenses.

    Central Nervous System

    Headache, migraine, dizziness, mental depression, exacerbation of chorea, mood disturbances, anxiety, irritability, exacerbation of epilepsy, dementia, growth potentiation of benign meningioma.

    Miscellaneous

    Increase or decrease in weight, arthralgia, glucose intolerance, edema, changes in libido, exacerbation of asthma, increased triglycerides, hypersensitivity.

    Additional postmarketing adverse reactions have been reported in patients receiving other forms of hormone therapy.

    Drug Interactions

    DRUG INTERACTIONS

    Data from a single-dose drug-drug interaction study involving CE and MPA indicate that the pharmacokinetic disposition of both drugs is not altered when the drugs are coadministered. No other clinical drug-drug interaction studies have been conducted with CE plus MPA.

    Metabolic Interactions

    In vitro and in vivo studies have shown that estrogens are metabolized partially by cytochrome P450 3A4 (CYP3A4). Therefore, inducers or 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.

    Aminoglutethimide administered concomitantly with MPA may significantly depress the bioavailability of MPA.

    Description

    DESCRIPTION

    Premarin (conjugated estrogens tablets, USP) for oral administration contains a mixture obtained exclusively from natural sources, occurring as the sodium salts of water-soluble estrogen sulfates blended to represent the average composition of material derived from pregnant mares' urine. It is a mixture of sodium estrone sulfate and sodium equilin sulfate. It contains as concomitant components, as sodium sulfate conjugates, 17 α-dihydroequilin, 17 α-estradiol and 17 β-dihydroequilin.

    Medroxyprogesterone acetate is a derivative of progesterone. It is a white to off-white, odorless, crystalline powder, stable in air, melting between 200°C and 210°C. It is freely soluble in chloroform, soluble in acetone and in dioxane, sparingly soluble in alcohol and in methanol, slightly soluble in ether, and insoluble in water. The chemical name for MPA is pregn-4-ene-3, 20-dione, 17-(acetyloxy)-6-methyl-, (6α)-. Its molecular formula is C 24 H 34 O 4 , with a molecular weight of 386.53. Its structural formula is:

    Referenced Image

    PREMPRO 0.3 mg/1.5 mg and 0.45 mg/1.5 mg tablets contain the following inactive ingredients: calcium phosphate tribasic, microcrystalline cellulose, carnauba wax, hypromellose, hydroxypropyl cellulose, sucrose, Eudragit NE 30D, lactose monohydrate, magnesium stearate, polyethylene glycol, titanium dioxide, yellow iron oxide, propylene glycol and black iron oxide.

    PREMPRO 0.625 mg/2.5 mg tablets contain the following inactive ingredients: calcium phosphate tribasic, microcrystalline cellulose, carnauba wax, hypromellose, hydroxypropyl cellulose, sucrose, Eudragit NE 30D, lactose monohydrate, magnesium stearate, polyethylene glycol, propylene glycol, titanium dioxide, red iron oxide, yellow iron oxide, and black iron oxide.

    PREMPRO 0.625 mg/5 mg tablets contain the following inactive ingredients: calcium phosphate tribasic, carnauba wax, Eudragit NE 30D, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, sucrose, titanium dioxide, triethyl citrate, FD&C Blue No. 2, black iron oxide, and propylene glycol.

    PREMPHASE

    Each maroon Premarin tablets for oral administration contain 0.625 mg of CE and the following inactive ingredients: calcium phosphate tribasic, carnauba wax, hydroxypropyl cellulose, microcrystalline cellulose, powdered cellulose, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, sucrose, titanium dioxide, propylene glycol, FD&C Blue No. 2, and FD&C Red No. 40. These tablets comply with USP Dissolution Test 5.

    Each light-blue tablet for oral administration contains 0.625 mg of CE, 5 mg of medroxyprogesterone acetate, and the following inactive ingredients: calcium phosphate tribasic, carnauba wax, Eudragit NE 30D, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, sucrose, titanium dioxide, triethyl citrate, FD&C Blue No. 2, black iron oxide, and propylene glycol.

    PREMPRO

    Tablet Strength

    Tablet Color Contains

    0.3 mg/1.5 mg

    Yellow iron oxide and black iron oxide

    0.45 mg/1.5 mg

    Yellow iron oxide and black iron oxide

    0.625 mg/2.5 mg

    Red iron oxide, yellow iron oxide, and black iron oxide

    0.625 mg/5 mg

    FD&C Blue No. 2 and black iron oxide

    PREMPHASE

    Tablet Strength

    Tablet Color Contains

    0.625 mg

    FD&C Blue No. 2 and FD&C Red No. 40

    0.625 mg/5 mg

    FD&C Blue No. 2 and black iron oxide

    Pharmacology

    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, which is 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 gonadotropins seen in postmenopausal women.

    Parenterally administered medroxyprogesterone acetate (MPA) inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation; although available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. MPA may achieve its beneficial effect on the endometrium in part by decreasing nuclear estrogen receptors and suppression of epithelial DNA synthesis in endometrial tissue. Androgenic and anabolic effects of MPA have been noted, but the drug is apparently devoid of significant estrogenic activity.

    Pharmacodynamics

    Currently, there are no pharmacodynamic data known for PREMPRO or PREMPHASE tablets.

    Pharmacokinetics

    Absorption

    PREMPRO and PREMPHASE contain a formulation of medroxyprogesterone acetate (MPA) that is immediately released and CE that are slowly released over several hours. Conjugated estrogens are water-soluble and are well-absorbed from the gastrointestinal tract after release from the drug formulation. MPA is well absorbed from the gastrointestinal tract. Table 3 and Table 4 summarize the mean pharmacokinetic parameters for select unconjugated and conjugated estrogens and medroxyprogesterone acetate following administration of PREMPRO to healthy, postmenopausal women.

    Table 3: Pharmacokinetic Parameters for Unconjugated and Conjugated Estrogens (CE) and Medroxyprogesterone Acetate (MPA)
    BA• = Baseline adjusted
    C max = peak plasma concentration
    t max = time peak concentration occurs
    t 1/2 = apparent terminal-phase disposition half-life (0.693/λ z )
    AUC = total area under the concentration-time curve

    DRUG

    2 × 0.625 mg CE/2.5 mg MPA
    Combination Tablets
    (n = 54)

    2 × 0.625 mg CE/5 mg MPA
    Combination Tablets
    (n = 51)

    PK Parameter
    Arithmetic
    Mean (%CV)

    C max
    (pg/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (pg∙h/mL)

    C max
    (pg/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (pg∙h/mL)

    Unconjugated Estrogens

    Estrone

    175
    (23)

    7.6
    (24)

    31.6
    (23)

    5358
    (34)

    124
    (43)

    10
    (35)

    62.2
    (137)

    6303
    (40)

    BA• -Estrone

    159
    (26)

    7.6
    (24)

    16.9
    (34)

    3313
    (40)

    104
    (49)

    10
    (35)

    26.0
    (100)

    3136
    (51)

    Equilin

    71
    (31)

    5.8
    (34)

    9.9
    (35)

    951
    (43)

    54
    (43)

    8.9
    (34)

    15.5
    (53)

    1179
    (56)

    PK Parameter
    Arithmetic
    Mean (%CV)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    Conjugated Estrogens

    Total Estrone

    6.6
    (38)

    6.1
    (28)

    20.7
    (34)

    116
    (59)

    6.3
    (48)

    9.1
    (29)

    23.6
    (36)

    151
    (42)

    BA• -Total Estrone

    6.4
    (39)

    6.1
    (28)

    15.4
    (34)

    100
    (57)

    6.2
    (48)

    9.1
    (29)

    20.6
    (35)

    139
    (40)

    Total Equilin

    5.1
    (45)

    4.6
    (35)

    11.4
    (25)

    50
    (70)

    4.2
    (52)

    7.0
    (36)

    17.2
    (131)

    72
    (50)

    PK Parameter
    Arithmetic Mean
    (%CV)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    Medroxyprogesterone Acetate

    MPA

    1.5
    (40)

    2.8
    (54)

    37.6
    (30)

    37
    (30)

    4.8
    (31)

    2.4
    (50)

    46.3
    (39)

    102
    (28)

    TABLE 4. Pharmacokinetic Parameters for Unconjugated and Conjugated Estrogens (CE) and Medroxyprogesterone Acetate (MPA)
    BA• = Baseline adjusted
    C max = peak plasma concentration
    t max = time peak concentration occurs
    t 1/2 = apparent terminal-phase disposition half-life (0.693/λ z )
    AUC = total area under the concentration-time curve

    DRUG

    4 × 0.45 mg CE/1.5 mg MPA Combination
    (n = 65)

    PK Parameter
    Arithmetic Mean (%CV)

    C max
    (pg/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (pg∙h/mL)

    Unconjugated Estrogens

    Estrone

    149
    (35)

    8.9
    (35)

    37.5
    (35)

    6641
    (39)

    BA• -Estrone

    130
    (40)

    8.9
    (35)

    21.2
    (35)

    3799
    (47)

    Equilin

    83
    (38)

    8.3
    (48)

    15.9
    (44)

    1889
    (40)

    PK Parameter
    Arithmetic Mean (%CV)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    Conjugated Estrogens

    Total Estrone

    5.4
    (49)

    7.9
    (48)

    22.4
    (53)

    119
    (48)

    BA• -Total Estrone

    5.2
    (48)

    7.9
    (48)

    15.1
    (29)

    100
    (47)

    Total Equilin

    4.3
    (42)

    6.5
    (45)

    11.6
    (31)

    74
    (48)

    PK Parameter
    Arithmetic Mean (%CV)

    C max
    (ng/mL)

    t max
    (h)

    t 1/2
    (h)

    AUC
    (ng∙h/mL)

    Medroxyprogesterone Acetate

    MPA

    0.7
    (66)

    2.0
    (52)

    26.2
    (35)

    5.0
    (61)

    Food-Effect: Single dose studies in healthy, postmenopausal women were conducted to investigate any potential drug interaction when PREMPRO or PREMPHASE is administered with a high-fat breakfast. Administration with food decreased the C max of total estrone by 18 to 34% and increased total equilin C max by 38% compared to the fasting state, with no other effect on the rate or extent of absorption of other conjugated or unconjugated estrogens. Administration with food approximately doubles MPA C max and increases MPA AUC by approximately 20 to 30%.

    Dose Proportionality: The C max and AUC values for MPA observed in two separate pharmacokinetic studies conducted with 2 PREMPRO 0.625 mg/2.5 mg or 2 PREMPRO or PREMPHASE 0.625 mg/5 mg tablets exhibited nonlinear dose proportionality; doubling the MPA dose from 2 × 2.5 to 2 × 5 mg increased the mean C max and AUC by 3.2- and 2.8-fold, respectively.

    The dose proportionality of estrogens and medroxyprogesterone acetate was assessed by combining pharmacokinetic data across another two studies totaling 61 healthy, postmenopausal women. Single CE doses of 2 × 0.3 mg, 2 × 0.45 mg, or 2 × 0.625 mg were administered either alone or in combination with medroxyprogesterone acetate doses of 2 × 1.5 mg or 2 × 2.5 mg. Most of the estrogen components demonstrated dose proportionality; however, several estrogen components did not. Medroxyprogesterone acetate pharmacokinetic parameters increased in a dose-proportional manner.

    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. MPA is approximately 90% bound to plasma proteins, but does not bind to SHBG.

    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 proportion of the circulating estrogens exist as sulfate conjugates, especially estrone sulfate, which serves as a circulating reservoir for the formation of more active estrogens. Metabolism and elimination of MPA occur primarily in the liver via hydroxylation, with subsequent conjugation and elimination in the urine.

    Excretion

    Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates. Most metabolites of MPA are excreted as glucuronide conjugates, with only minor amounts excreted as sulfates.

    Use in Specific Populations

    No pharmacokinetic studies were conducted in specific populations, including patients with renal or hepatic impairment.

    Nonclinical Toxicology

    NONCLINICAL TOXICOLOGY

    Carcinogenesis, Mutagenesis, Impairment of Fertility

    Long-term continuous administration of natural and synthetic estrogens in certain animal species increases the frequency of carcinomas of the breasts, uterus, cervix, vagina, testis, and liver [see Warnings and Precautions (5.2) ] .

    MPA was not mutagenic in a battery of in vitro or in vivo genetic toxicity assays [see Warnings and Precautions (5.7) ] .

    Clinical Studies

    CLINICAL STUDIES

    Effects on Vasomotor Symptoms

    In the first year of the Health and Osteoporosis, Progestin and Estrogen (HOPE) Study, a total of 2,805 postmenopausal women (average age 53.3 ± 4.9 years) were randomly assigned to one of eight treatment groups of either placebo or CE, with or without MPA. Efficacy for vasomotor symptoms was assessed during the first 12 weeks of treatment in a subset of symptomatic women (n = 241) who had at least seven moderate to severe hot flushes daily, or at least 50 moderate to severe hot flushes during the week before randomization. With PREMPRO 0.625 mg/2.5 mg, 0.45 mg/1.5 mg, and 0.3 mg/1.5 mg, the relief of both the frequency and severity of moderate to severe vasomotor symptoms was shown to be statistically improved compared to placebo at weeks 4 and 12. Table 5 shows the adjusted mean number of hot flushes in the PREMPRO 0.625 mg/2.5 mg, 0.45 mg/1.5 mg, 0.3 mg/1.5 mg, and placebo groups during the initial 12-week period.

    Table 5: Summary Tabulation of the Number of Hot Flushes Per Day – Mean Values and Comparisons Between the Active Treatment Groups and the Placebo Group – Patients with At Least 7 Moderate to Severe Flushes Per Day or At Least 50 Per Week at Baseline, Last Observation Carries Forward (LOCF)

    Treatment Identified by dosage (mg) of Premarin/MPA or placebo.
    (No. of Patients)


    -------------------No. of Hot Flushes/Day-----------------

    Time Period
    (week)

    Baseline
    Mean ± SD

    Observed
    Mean ± SD

    Mean
    Change ± SD

    p-Values
    vs. Placebo There were no statistically significant differences between the 0.625 mg/2.5 mg, 0.45 mg/1.5 mg, and 0.3 mg/1.5 mg groups at any time period.

    0.625 mg/2.5 mg
    (n = 34)

    4

    11.98 ± 3.54

    3.19 ± 3.74

    -8.78 ± 4.72

    <0.001

    12

    11.98 ± 3.54

    1.16 ± 2.22

    -10.82 ± 4.61

    <0.001

    0.45 mg/1.5 mg
    (n = 29)

    4

    12.61 ± 4.29

    3.64 ± 3.61

    -8.98 ± 4.74

    <0.001

    12

    12.61 ± 4.29

    1.69 ± 3.36

    -10.92 ± 4.63

    <0.001

    0.3 mg/1.5 mg
    (n = 33)

    4

    11.30 ± 3.13

    3.70 ± 3.29

    -7.60 ± 4.71

    <0.001

    12

    11.30 ± 3.13

    1.31 ± 2.82

    -10.00 ± 4.60

    <0.001

    Placebo
    (n = 28)

    4

    11.69 ± 3.87

    7.89 ± 5.28

    -3.80 ± 4.71

    12

    11.69 ± 3.87

    5.71 ± 5.22

    -5.98 ± 4.60

    Effects on Vulvar and Vaginal Atrophy

    Results of vaginal maturation indexes at cycles 6 and 13 showed that the differences from placebo were statistically significant (p < 0.001) for all treatment groups.

    Effects on the Endometrium

    In a 1-year clinical trial of 1,376 women (average age 54 ± 4.6 years) randomized to PREMPRO 0.625 mg/2.5 mg (n = 340), PREMPRO 0.625 mg/5 mg (n = 338), PREMPHASE 0.625 mg/5 mg (n = 351), or Premarin 0.625 mg alone (n = 347), results of evaluable biopsies at 12 months (n = 279, 274, 277, and 283, respectively) showed a reduced risk of endometrial hyperplasia in the two PREMPRO treatment groups (less than 1%) and in the PREMPHASE treatment group (less than 1%; 1% when focal hyperplasia was included) compared to the Premarin group (8%; 20% when focal hyperplasia was included), see Table 6 .

    Table 6: Incidence of Endometrial Hyperplasia After One Year of Treatment

    --------------------------Groups-------------------------

    PREMPRO

    PREMPRO

    PREMPHASE

    Premarin

    0.625 mg/2.5 mg

    0.625 mg/5 mg

    0.625 mg/5 mg

    0.625 mg

    Total number of patients

    340

    338

    351

    347

    Number of patients with evaluable biopsies

    279

    274

    277

    283

    No. (%) of patients with biopsies:

    • All focal and non-focal hyperplasia

    2 (<1) Significant (p < 0.001) in comparison with Premarin (0.625 mg) alone.

    0 (0)

    3 (1)

    57 (20)

    • Excluding focal cystic hyperplasia

    2 (<1)

    0 (0)

    1 (<1)

    25 (8)

    In the first year of the Health and Osteoporosis, Progestin and Estrogen (HOPE) Study, 2,001 women (average age 53.3 ± 4.9 years), of whom 88% were Caucasian, were treated with either Premarin 0.625 mg alone (n = 348), Premarin 0.45 mg alone (n = 338), Premarin 0.3 mg alone (n = 326) or PREMPRO 0.625 mg/2.5 mg (n = 331), PREMPRO 0.45 mg/1.5 mg (n = 331) or PREMPRO 0.3 mg/1.5 mg (n = 327). Results of evaluable endometrial biopsies at 12 months showed a reduced risk of endometrial hyperplasia or cancer in the PREMPRO treatment groups compared with the corresponding Premarin alone treatment groups, except for the PREMPRO 0.3 mg/1.5 mg and Premarin 0.3 mg alone groups, in each of which there was only 1 case, see Table 7 .

    No endometrial hyperplasia or cancer was noted in those patients treated with the continuous combined regimens who continued for a second year in the osteoporosis and metabolic substudy of the HOPE study, see Table 8 .

    Table 7: Incidence of Endometrial Hyperplasia/Cancer All cases of hyperplasia/cancer were endometrial hyperplasia, except for 1 patient in the Premarin 0.3 mg group diagnosed with endometrial cancer based on endometrial biopsy and 1 patient in the Premarin/MPA 0.45 mg/1.5 mg group diagnosed with endometrial cancer based on endometrial biopsy. After One Year of Treatment Two (2) primary pathologists evaluated each endometrial biopsy. Where there was lack of agreement on the presence or absence of hyperplasia/cancer between the two, a third pathologist adjudicated (consensus).

    -----------------------------------Groups---------------------------------

    Patient

    Prempro
    0.625 mg/2.5 mg

    Premarin
    0.625 mg

    Prempro
    0.45 mg/1.5 mg

    Premarin
    0.45 mg

    Prempro
    0.3 mg/1.5 mg

    Premarin
    0.3 mg

    Total number of patients

    331

    348

    331

    338

    327

    326

    Number of patients with evaluable biopsies

    278

    249

    272

    279

    271

    269

    No. (%) of patients with biopsies:

    • Hyperplasia/cancer
    (consensus For an endometrial biopsy to be counted as consensus endometrial hyperplasia or cancer, at least 2 pathologists had to agree on the diagnosis. )

    0 (0) Significant (p < 0.05) in comparison with corresponding dose of Premarin alone.

    20 (8)

    1 (<1) ,

    9 (3)

    1 (<1) Non-significant in comparison with corresponding dose of Premarin alone.

    1 (<1)

    Table 8: Osteoporosis and Metabolic Substudy, Incidence of Endometrial Hyperplasia/Cancer All cases of hyperplasia/cancer were endometrial hyperplasia in patients who continued for a second year in the osteoporosis and metabolic substudy of the HOPE study. After Two Years of Treatment Two (2) primary pathologists evaluated each endometrial biopsy. Where there was lack of agreement on the presence or absence of hyperplasia/cancer between the two, a third pathologist adjudicated (consensus).

    -------------------------------Groups------------------------------

    Patient

    Prempro
    0.625 mg/2.5 mg

    Premarin
    0.625 mg

    Prempro
    0.45 mg/1.5 mg

    Premarin
    0.45 mg

    Prempro
    0.3 mg/1.5 mg

    Premarin
    0.3 mg

    Total number of patients

    75

    65

    75

    74

    79

    73

    Number of patients with evaluable biopsies

    62

    55

    69

    67

    75

    63

    No. (%) of patients with biopsies:

    • Hyperplasia/cancer
    (consensus For an endometrial biopsy to be counted as consensus endometrial hyperplasia or cancer, at least 2 pathologists had to agree on the diagnosis. )

    0 (0) Significant (p < 0.05) in comparison with corresponding dose of Premarin alone.

    15 (27)

    0 (0)

    10 (15)

    0 (0)

    2 (3)

    Effects on Uterine Bleeding or Spotting

    The effects of PREMPRO on uterine bleeding or spotting, as recorded on daily diary cards, were evaluated in 2 clinical trials. Results are shown in Figures 1 and 2.

    Referenced Image

    Note: The percentage of patients who were amenorrheic in a given cycle and through cycle 13 is shown. If data were missing, the bleeding value from the last reported day was carried forward (LOCF).

    Referenced Image

    Note: The percentage of patients who were amenorrheic in a given cycle and through cycle 13 is shown. If data were missing, the bleeding value from the last reported day was carried forward (LOCF).

    Effects on Bone Mineral Density

    Health and Osteoporosis, Progestin and Estrogen (HOPE) Study

    The HOPE study was a double-blind, randomized, placebo/active-drug-controlled, multicenter study of healthy postmenopausal women with an intact uterus. Subjects (mean age 53.3 ± 4.9 years) were 2.3 ± 0.9 years on average since menopause and took one 600 mg tablet of elemental calcium (Caltrate™) daily. Subjects were not given Vitamin D supplements. They were treated with PREMPRO 0.625 mg/2.5 mg, 0.45 mg/1.5 mg or 0.3 mg/1.5 mg, comparable doses of Premarin alone, or placebo. Prevention of bone loss was assessed by measurement of bone mineral density (BMD), primarily at the anteroposterior lumbar spine (L 2 to L 4 ). Secondarily, BMD measurements of the total body, femoral neck, and trochanter were also analyzed. Serum osteocalcin, urinary calcium, and N-telopeptide were used as bone turnover markers (BTM) at cycles 6, 13, 19, and 26.

    Intent-to-treat subjects

    All active treatment groups showed significant differences from placebo in each of the four BMD endpoints. These significant differences were seen at cycles 6, 13, 19, and 26.

    The percent changes from baseline to final evaluation are shown in Table 9.

    Table 9: Percent Change in Bone Mineral Density: Comparison Between Active and Placebo Groups in the Intent-To-Treat Population, LOCF

    Region Evaluated Treatment Group Identified by dosage (mg/mg) of Premarin/MPA or placebo.

    No. of Subjects

    Baseline
    (g/cm 2 )
    Mean ± SD

    Change from
    Baseline (%) Adjusted
    Mean ± SE

    p-Value
    vs.
    Placebo

    L 2 to L 4 BMD

    0.625/2.5

    81

    1.14 ± 0.16

    3.28 ± 0.37

    <0.001

    0.45/1.5

    89

    1.16 ± 0.14

    2.18 ± 0.35

    <0.001

    0.3/1.5

    90

    1.14 ± 0.15

    1.71 ± 0.35

    <0.001

    Placebo

    85

    1.14 ± 0.14

    -2.45 ± 0.36

    Total body BMD

    0.625/2.5

    81

    1.14 ± 0.08

    0.87 ± 0.17

    <0.001

    0.45/1.5

    89

    1.14 ± 0.07

    0.59 ± 0.17

    <0.001

    0.3/1.5

    91

    1.13 ± 0.08

    0.60 ± 0.16

    <0.001

    Placebo

    85

    1.13 ± 0.08

    -1.50 ± 0.17

    Femoral neck BMD

    0.625/2.5

    81

    0.89 ± 0.14

    1.62 ± 0.46

    <0.001

    0.45/1.5

    89

    0.89 ± 0.12

    1.48 ± 0.44

    <0.001

    0.3/1.5

    91

    0.86 ± 0.11

    1.31 ± 0.43

    <0.001

    Placebo

    85

    0.88 ± 0.14

    -1.72 ± 0.45

    Femoral trochanter BMD

    0.625/2.5

    81

    0.77 ± 0.14

    3.35 ± 0.59

    0.002

    0.45/1.5

    89

    0.76 ± 0.12

    2.84 ± 0.57

    0.011

    0.3/1.5

    91

    0.76 ± 0.12

    3.93 ± 0.56

    <0.001

    Placebo

    85

    0.75 ± 0.12

    0.81 ± 0.58

    Figure 3 shows the cumulative percentage of subjects with percent changes from baseline in spine BMD equal to or greater than the percent change shown on the x-axis.

    Referenced Image

    The mean percent changes from baseline in L 2 to L 4 BMD for women who completed the bone density study are shown with standard error bars by treatment group in Figure 4. Significant differences between each of the PREMPRO dosage groups and placebo were found at cycles 6, 13, 19, and 26.

    Referenced Image

    The bone turnover markers, serum osteocalcin and urinary N-telopeptide, significantly decreased (p < 0.001) in all active-treatment groups at cycles 6, 13, 19, and 26 compared with the placebo group. Larger mean decreases from baseline were seen with the active groups than with the placebo group. Significant differences from placebo were seen less frequently in urine calcium; only with PREMPRO 0.625 mg/2.5 mg and 0.45 mg/1.5 mg were there significantly larger mean decreases than with placebo at 3 or more of the 4 time points.

    Women's Health Initiative Studies

    The WHI enrolled approximately 27,000 predominantly healthy postmenopausal women in two substudies to assess the risks and benefits of daily oral CE (0.625 mg)-alone or in combination with MPA (2.5 mg) compared to placebo in the prevention of certain chronic diseases. The primary endpoint was the incidence of CHD (defined as nonfatal MI, silent MI and CHD death), with invasive breast cancer as the primary adverse outcome. A "global index" included the earliest occurrence of CHD, invasive breast cancer, stroke, PE, endometrial cancer (only in the CE plus MPA substudy), colorectal cancer, hip fracture, or death due to other causes. These substudies did not evaluate the effects of CE plus MPA or CE-alone on menopausal symptoms.

    WHI Estrogen Plus Progestin Substudy

    The WHI estrogen plus progestin substudy was stopped early. According to the predefined stopping rule, after an average follow-up of 5.6 years of treatment, the increased risk of invasive breast cancer and cardiovascular events exceeded the specified benefits included in the "global index." The absolute excess risk of events included in the "global index" was 19 per 10,000 women-years.

    For those outcomes included in the WHI "global index" that reached statistical significance after 5.6 years of follow-up, the absolute excess risks per 10,000 women-years in the group treated with CE plus MPA were 7 more CHD events, 8 more strokes, 10 more PEs, and 8 more invasive breast cancers, while the absolute risk reductions per 10,000 women-years were 6 fewer colorectal cancers and 5 fewer hip fractures.

    Results of the CE plus MPA substudy, which included 16,608 women (average 63 years of age, range 50 to 79; 83.9% White, 6.8% Black, 5.4% Hispanic, 3.9% Other) are presented in Table 10. These results reflect centrally adjudicated data after an average follow-up of 5.6 years.

    TABLE 10: Relative and Absolute Risk Seen in the Estrogen Plus Progestin Substudy of WHI at an Average of 5.6 Years Adapted from numerous WHI publications. WHI publications can be viewed at www.nhlbi.nih.gov/whi . , Results are based on centrally adjudicated data.

    Relative Risk
    CE/MPA vs. Placebo
    (95% nCI Nominal confidence intervals unadjusted for multiple looks and multiple comparisons. )


    CE/MPA
    n = 8,506


    Placebo
    n = 8,102

    Event

    Absolute Risk per 10,000
    Women-Years

    CHD events

    1.23 (0.99–1.53)

    41

    34

    Non-fatal MI

    1.28 (1.00–1.63)

    31

    25

    CHD death

    1.10 (0.70–1.75)

    8

    8

    All Strokes

    1.31 (1.03–1.68)

    33

    25

    Ischemic stroke

    1.44 (1.09–1.90)

    26

    18

    Deep vein thrombosis Not included in "global index."

    1.95 (1.43–2.67)

    26

    13

    Pulmonary embolism

    2.13 (1.45–3.11)

    18

    8

    Invasive breast cancer Includes metastatic and non-metastatic breast cancer, with the exception of in situ breast cancer.

    1.24 (1.01–1.54)

    41

    33

    Colorectal cancer

    0.61 (0.42–0.87)

    10

    16

    Endometrial cancer

    0.81 (0.48–1.36)

    6

    7

    Cervical cancer

    1.44 (0.47–4.42)

    2

    1

    Hip fracture

    0.67 (0.47–0.96)

    11

    16

    Vertebral fractures

    0.65 (0.46–0.92)

    11

    17

    Lower arm/wrist fractures

    0.71 (0.59–0.85)

    44

    62

    Total fractures

    0.76 (0.69–0.83)

    152

    199

    Overall Mortality All deaths, except from breast or colorectal cancer, definite or probable CHD, PE or cerebrovascular disease.

    1.00 (0.83–1.19)

    52

    52

    Global Index A subset of the events was combined in a "global index" defined as the earliest occurrence of CHD events, invasive breast cancer, stroke, pulmonary embolism, colorectal cancer, hip fracture, or death due to other causes.

    1.13 (1.02–1.25)

    184

    165

    Timing of the initiation of estrogen plus progestin therapy relative to the start of menopause may affect the overall risk benefit profile. The WHI estrogen plus progestin substudy stratified by age showed in women 50 to 59 years of age, a non-significant trend toward reduced risk for overall mortality [hazard ratio (HR) 0.69 (95% CI, 0.44–1.07)] .

    WHI Estrogen-Alone Substudy

    The WHI estrogen-alone substudy was stopped early because an increased risk of stroke was observed, and it was deemed that no further information would be obtained regarding the risks and benefits of estrogen-alone in predetermined primary endpoints.

    Results of the estrogen-alone substudy, which included 10,739 women (average 63 years of age, range 50 to 79; 75.3% White, 15.1% Black, 6.1% Hispanic, 3.6% Other) after an average follow-up of 7.1 years, are presented in Table 11 .

    Table 11: Relative and Absolute Risk Seen in the Estrogen-Alone Substudy of WHI Adapted from numerous WHI publications. WHI publications can be viewed at www.nhlbi.nih.gov/whi .

    Relative Risk
    CE vs. Placebo
    (95% nCI Nominal confidence intervals unadjusted for multiple looks and multiple comparisons. )


    CE
    n = 5,310


    Placebo
    n = 5,429

    Event

    Absolute Risk per 10,000
    Women-Years

    CHD events Results are based on centrally adjudicated data for an average follow-up of 7.1 years.

    0.95 (0.78–1.16)

    54

    57

    Non-fatal MI

    0.91 (0.73–1.14)

    40

    43

    CHD death

    1.01 (0.71–1.43)

    16

    16

    All Strokes

    1.33 (1.05–1.68)

    45

    33

    Ischemic stroke

    1.55 (1.19–2.01)

    38

    25

    Deep vein thrombosis , Not included in "global index."

    1.47 (1.06–2.06)

    23

    15

    Pulmonary embolism

    1.37 (0.90–2.07)

    14

    10

    Invasive breast cancer

    0.80 (0.62–1.04)

    28

    34

    Colorectal cancer Results are based on an average follow-up of 6.8 years.

    1.08 (0.75–1.55)

    17

    16

    Hip fracture

    0.65 (0.45–0.94)

    12

    19

    Vertebral fractures ,

    0.64 (0.44–0.93)

    11

    18

    Lower arm/wrist fractures ,

    0.58 (0.47–0.72)

    35

    59

    Total fractures ,

    0.71 (0.64–0.80)

    144

    197

    Death due to other causes , All deaths, except from breast or colorectal cancer, definite or probable CHD, PE or cerebrovascular disease.

    1.08 (0.88–1.32)

    53

    50

    Overall mortality ,

    1.04 (0.88–1.22)

    79

    75

    Global Index A subset of the events was combined in a "global index" defined as the earliest occurrence of CHD events, invasive breast cancer, stroke, pulmonary embolism, colorectal cancer, hip fracture, or death due to other causes.

    1.02 (0.92–1.13)

    206

    201

    For those outcomes included in the WHI "global index" that reached statistical significance, the absolute excess risk per 10,000 women-years in the group treated with CE-alone was 12 more strokes while the absolute risk reduction per 10,000 women-years was 7 fewer hip fractures. 9 The absolute excess risk of events included in the "global index" was a non-significant 5 events per 10,000 women-years. There was no difference between the groups in terms of all-cause mortality.

    No overall difference for primary CHD events (nonfatal MI, silent MI and CHD death) and invasive breast cancer incidence in women receiving CE-alone compared with placebo was reported in final centrally adjudicated results from the estrogen-alone substudy, after an average follow up of 7.1 years.

    Centrally adjudicated results for stroke events from the estrogen-alone substudy, after an average follow-up of 7.1 years, reported no significant difference in distribution of stroke subtype or severity, including fatal strokes, in women receiving CE-alone compared to placebo. Estrogen-alone increased the risk for ischemic stroke, and this excess risk was present in all subgroups of women examined. 10

    Timing of the initiation of estrogen-alone therapy relative to the start of menopause may affect the overall risk benefit profile. The WHI estrogen-alone substudy, stratified by age, showed in women 50 to 59 years of age a non-significant trend toward reduced risk for CHD [HR 0.63 (95% CI, 0.36–1.09)] and overall mortality [HR 0.71 (95% CI, 0.46–1.11)] .

    Women's Health Initiative Memory Study

    The WHIMS estrogen plus progestin ancillary study of WHI enrolled 4,532 predominantly healthy postmenopausal women 65 years of age and older (47% were 65 to 69 years of age; 35% were 70 to 74 years of age; and 18% were 75 years of age and older) to evaluate the effects of daily CE (0.625 mg) plus MPA (2.5 mg) on the incidence of probable dementia (primary outcome) compared to placebo.

    After an average follow-up of 4 years, the relative risk of probable dementia for CE plus MPA versus placebo was 2.05 (95% 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-years. Probable dementia as defined in this study included Alzheimer's disease (AD), vascular dementia (VaD) and mixed types (having features of both AD and VaD). The most common classification of probable dementia in the treatment group and the placebo group was AD. Since the ancillary study was conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women [see Warnings and Precautions (5.3) , and Use in Specific Populations (8.5) ] .

    The WHIMS estrogen-alone ancillary study of WHI enrolled 2,947 predominantly healthy hysterectomized postmenopausal women 65 to 79 years of age and older (45% were 65 to 69 years of age; 36% were 70 to 74 years of age; 19% were 75 years of age and older) to evaluate the effects of daily CE (0.625 mg)-alone on the incidence of probable dementia (primary outcome) compared to placebo.

    After an average follow-up of 5.2 years, the relative risk of probable dementia for CE-alone versus placebo was 1.49 (95% 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-years. Probable dementia as defined in this study included AD, VaD and mixed types (having features of both AD and VaD). The most common classification of probable dementia in the treatment group and the placebo group was AD. Since the ancillary study was conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women [see Warnings and Precautions (5.3) , and Use in Specific Populations (8.5) ] .

    When data from the two populations were pooled as planned in the WHIMS protocol, the reported overall relative risk for probable dementia was 1.76 (95% CI, 1.19–2.60). Differences between groups became apparent in the first year of treatment. It is unknown whether these findings apply to younger postmenopausal women [see Warnings and Precautions (5.3) , and Use in Specific Populations (8.5) ] .

    How Supplied/Storage & Handling

    HOW SUPPLIED/STORAGE AND HANDLING

    How Supplied

    PREMPRO therapy consists of a single tablet to be taken once daily.

    PREMPRO 0.3 mg/1.5 mg

    NDC 0046-1105-11, carton includes 1 blister card containing 28 oval, cream tablets.

    PREMPRO 0.45 mg/1.5 mg

    NDC 0046-1106-11, carton includes 1 blister card containing 28 oval, gold tablets.

    PREMPRO 0.625 mg/2.5 mg

    NDC 0046-1107-11, carton includes 1 blister card containing 28 oval, peach tablets.

    PREMPRO 0.625 mg/5 mg

    NDC 0046-1108-11, carton includes 1 blister card containing 28 oval, light-blue tablets.

    PREMPHASE therapy consists of two separate tablets; one maroon Premarin tablet taken daily on days 1 through 14 and one light-blue tablet taken on days 15 through 28.

    NDC 0046-2575-12, carton includes 1 blister card containing 28 tablets (14 oval, maroon Premarin tablets and 14 oval, light-blue tablets).

    The appearance of PREMPRO tablets is a trademark of Pfizer Inc.

    The appearance of PREMARIN tablets is a trademark of Pfizer Inc. The appearance of the conjugated estrogens/medroxyprogesterone acetate combination tablets is a trademark.

    Storage and Handling

    Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].

    Mechanism of Action

    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, which is 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 gonadotropins seen in postmenopausal women.

    Parenterally administered medroxyprogesterone acetate (MPA) inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation; although available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. MPA may achieve its beneficial effect on the endometrium in part by decreasing nuclear estrogen receptors and suppression of epithelial DNA synthesis in endometrial tissue. Androgenic and anabolic effects of MPA have been noted, but the drug is apparently devoid of significant estrogenic activity.

    Data SourceWe receive information directly from the FDA and PrescriberPoint is updated as frequently as changes are made available
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