Other
Estrogen Plus Progestin Therapy
Cardiovascular Disorders and Probable Dementia
The Women's Health Initiative (WHI) estrogen plus progestin substudy reported increased risks 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 (14.5)].
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 and 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 (14.6)].
Do not use estrogen plus progestogen therapy for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1, 5.3), and Clinical Studies (14.5, 14.6)].
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 (14.5)].
Only daily oral 0.625 mg CE and 2.5 mg MPA were studied in the estrogen plus progestin substudy of the WHI. Therefore, the relevance of the WHI findings regarding adverse cardiovascular events, dementia and breast cancer to lower CE plus other MPA doses, other routes of administration, or other estrogen plus progestogen products is not known. Without such data, it is not possible to definitively exclude these risks or determine the extent of these risks for other products. Discuss with your patient the benefits and risks of estrogen plus progestogen therapy, taking into account her individual risk profile.
Prescribe estrogens with or without progestogens 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 progestogen 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
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 (14.5)].
The WHIMS estrogen-alone ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age and 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 (14.6)].
Do not use estrogen-alone therapy for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1, 5.3), and Clinical Studies (14.5, 14.6)].
Only daily oral 0.625 mg CE was studied in the estrogen-alone substudy of the WHI. Therefore, the relevance of the WHI findings regarding adverse cardiovascular events and dementia to lower CE doses, other routes of administration, or other estrogen-alone products is not known. Without such data, it is not possible to definitively exclude these risks or determine the extent of these risks for other products. Discuss with your patient the benefits and risks of estrogen-alone therapy, taking into account her individual risk profile.
Prescribe estrogens with or without progestogens at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.
Limitation of Use
When prescribing solely for the treatment of moderate to severe symptoms of vulvar and vaginal atrophy due to menopause, first consider the use of topical vaginal products.
Limitation of Use
When prescribing solely for the prevention of postmenopausal osteoporosis, first consider the use of non-estrogen medications. Consider estrogen therapy only for women at significant risk of osteoporosis.
Stroke
The WHI estrogen plus progestin substudy reported a statistically significant increased risk of stroke 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 strokes per 10,000 women-years) [see Clinical Studies (14.5)]. The increase in risk was demonstrated after the first year and persisted.1 Immediately discontinue estrogen with or without progestogen therapy if a stroke occurs or is suspected.
The WHI estrogen-alone substudy reported a statistically significant increased risk of stroke 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 strokes per 10,000 women-years, respectively). The increase in risk was demonstrated in year 1 and persisted [see Clinical Studies (14.5)]. Immediately discontinue estrogen-alone therapy if a stroke occurs or is suspected.
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
The WHI estrogen plus progestin substudy reported an increased risk (not statistically significant) of coronary heart disease (CHD) events (defined as nonfatal MI, silent MI, or CHD death) in those 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 (14.5)].
The WHI estrogen-alone substudy reported no overall effect on CHD events in women receiving estrogen-alone compared to placebo 2 [see Clinical Studies (14.5)].
Subgroup analyses of women 50 to 59 years of age, who were less than 10 years since menopause, suggest a reduction (not statistically significant) in CHD events in those women receiving daily CE (0.625 mg)-alone compared to placebo (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 CHD. There were more CHD events in the CE plus MPA-treated group than in the placebo group in year 1, but not during the subsequent years. Two thousand three hundred 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
The WHI estrogen plus progestin substudy reported a statistically significant 2-fold greater rate of VTE (DVT and PE) 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 (14.5)]. Immediately discontinue estrogen plus progestogen therapy if a VTE occurs or is suspected.
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 (14.5)]. Immediately discontinue estrogen-alone therapy if a VTE occurs or is suspected.
If feasible, discontinue estrogens at least 4 to 6 weeks before surgery of the type associated with an increased risk of thromboembolism, or during periods of prolonged immobilization.
Breast Cancer
After a mean follow-up of 5.6 years, the WHI substudy of daily CE (0.625 mg) plus MPA (2.5 mg) reported an increased risk of invasive breast cancer in women who took daily CE plus MPA compared to placebo.
In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years, for CE plus MPA compared with 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 5 [see Clinical Studies (14.5)].
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-alone was not associated with an increased risk of invasive breast cancer [relative risk (RR) 0.80] compared to placebo 6 [see Clinical Studies (14.5)].
Consistent with the WHI clinical trials, observational studies have also reported an increased risk of breast cancer with estrogen plus progestin therapy, and a smaller increase in the risk for breast cancer with estrogen-alone therapy, after several years of use. The risk increased with duration of use, and appeared to return to baseline over about 5 years after stopping treatment (only the observational studies have substantial data on risk after stopping). Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with estrogen plus progestin therapy as compared to estrogen-alone therapy. These studies have not generally 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 therapy has been reported to result in an increase in abnormal mammograms requiring further evaluation.
In a one-year trial among 1,176 women who received either unopposed 1 mg estradiol or a combination of 1 mg estradiol plus one of three different doses of NETA (0.1, 0.25, 0.5 mg), seven new cases of breast cancer were diagnosed, two of which occurred among the group of 295 women treated with Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg and two of which occurred among the group of 294 women treated with 1 mg estradiol/0.1 mg NETA.
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
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-fold greater than in nonusers, 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. 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 progestogen therapy is important. Perform adequate diagnostic measures, including directed or random endometrial sampling when indicated, to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding with unknown etiology.
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 progestogen to estrogen therapy in postmenopausal women has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer.
Endometrial hyperplasia occured at a rate of approximately 1 percent or less with Estradiol/Norethindrone Acetate Tablets in a clinical trial.
Ovarian Cancer
The CE plus MPA substudy of WHI reported that estrogen plus progestin increased the risk of ovarian cancer. After an average follow-up of 5.6 years, the relative risk for ovarian cancer for CE plus MPA versus placebo was 1.58 (95 percent confidence interval [CI], 0.77-3.24), but it was not statistically significant. 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.
Genitourinary System
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; pre-menstrual-like syndrome; cystitis-like syndrome; ovarian cancer; endometrial hyperplasia; endometrial cancer.
Breast
Tenderness, enlargement, pain, nipple discharge, galactorrhea; fibrocystic breast changes; breast cancer.
Cardiovascular
Deep and superficial venous thrombosis; pulmonary embolism; thrombophlebitis; myocardial infarction, stroke; increase in blood pressure.
Gastrointestinal
Nausea, vomiting; changes in appetite; cholestatic jaundice; abdominal pain/cramps, flatulence, bloating; increased incidence of gallbladder disease and pancreatitis.
Skin
Chloasma or melasma that may persist when drug is discontinued; erythema multiforme; erythema nodosum; hemorrhagic eruption; loss of scalp hair; seborrhea; hirsutism; itching; skin rash; pruritus.
Eyes
Retinal vascular thrombosis, intolerance to contact lenses.
Central Nervous System
Headache; migraine; dizziness; mental depression; chorea; insomnia; nervousness; mood disturbances; irritability; exacerbation of epilepsy; dementia.
Miscellaneous
Increase or decrease in weight; edema; leg cramps; changes in libido; fatigue; exacerbation of asthma; increased triglycerides; hypersensitivity; anaphylactoid/anaphylactic reactions.
Estradiol
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 result in adverse reactions.
Norethindrone Acetate
Drugs or herbal products that induce or inhibit cytochrome P-450 enzymes, including CYP3A4, may decrease or increase the serum concentrations of norethindrone.
Risk Summary
Estradiol/Norethindrone Acetate Tablets are not indicated for use in pregnancy. There are no data with the use of Estradiol/Norethindrone Acetate Tablets in pregnant women; however, epidemiologic studies and meta-analyses have not found an increased risk of genital or nongenital birth defects (including cardiac anomalities 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.
Risk Summary
Estrogens plus progestogens are present in human milk and 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 breastfeeding should be considered along with the mother's clinical need for Estradiol/Norethindrone Acetate Tablets and any potential adverse effects on the breastfed child from Estradiol/Norethindrone Acetate Tablets or from the underlying maternal condition.
The Women's Health Initiative Studies
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 (14.5)].
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 (14.5)].
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. It is unknown whether this finding applies to younger postmenopausal women [see Warnings and Precautions (5.3), and Clinical Studies (14.6)].
Since both ancillary studies were conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women8 [see Warnings and Precautions (5.3), and Clinical Studies (14.6)].
Absorption
Estradiol
Estradiol is absorbed through the gastrointestinal tract. Following oral administration of Estradiol/Norethindrone Acetate tablets, peak plasma estradiol concentrations are reached within 5 to 8 hours. The oral bioavailability of estradiol following administration of Estradiol/Norethindrone Acetate Tablets, 1 mg/0.5 mg when compared to a combination oral solution is 53%. Administration of Estradiol/Norethindrone Acetate Tablets, 1 mg/0.5 mg with food did not modify the bioavailability of estradiol.
Norethindrone Acetate
After oral administration, norethindrone acetate is absorbed and transformed to norethindrone. Norethindrone reaches a peak plasma concentration within 0.5 to 1.5 hours after the administration of Estradiol/Norethindrone Acetate Tablets. The oral bioavailability of norethindrone following administration of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg when compared to a combination oral solution is 100%. Administration of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg with food increases norethindrone AUC0-72 by 19% and decreases Cmax by 36%.
The pharmacokinetic parameters of estradiol (E2), estrone (E1), and norethindrone (NET) following oral administration of 1 Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg or 2 Estradiol/Norethindrone Acetate Tablets 0.5 mg/0.1 mg tablet(s) to healthy postmenopausal women are summarized in Table 3.
| 1 × Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg (n=24) Mean geometric mean; (%CV)geometric % coefficient of variation; | 2 × Estradiol/Norethindrone Acetate Tablets 0.5 mg/0.1 mg (n=24) Mean | |
|---|---|---|
| AUC = area under the curve, 0 – last quantifiable sample | ||
| Cmax = maximum plasma concentration, | ||
| tmax = time at maximum plasma concentration, | ||
| t1/2 = half-life, | ||
| Estradiol baseline unadjusted data; (E2) | ||
| AUC0-t (pg/mL*h) | 766.5 (48) | 697.3 (53) |
| Cmax (pg/mL) | 26.8 (36) | 26.5 (37) |
| tmax (h): median (range) | 6.0 (0.5-16.0) | 6.5 (0.5-16.0) |
| t1/2 (h) baseline unadjusted data ; | 14.0 n=18; (29) | 14.5 n=16; (27) |
| Estrone | ||
| AUC0-t (pg/mL*h) | 4469.1 (48) | 4506.4 (44) |
| Cmax (pg/mL) | 195.5 (37) | 199.5 (30) |
| tmax (h): median (range) | 6.0 (1.0-9.0) | 6.0 (2.0-9.0) |
| t1/2 (h) | 10.7 (44) n=13; | 11.8 (25) |
| Norethindrone (NET) | ||
| AUC0-t (pg/mL*h) | 21043 (41) | 8407.2 (43) |
| Cmax (pg/mL) | 5249.5 (47) | 2375.4 (41) |
| tmax (h) : median (range) | 0.7 (0.7-1.25) | 0.8 (0.7-1.3) |
| t1/2 (h) | 9.8 (32) n=22; | 11.4 (36) n=21 |
Following continuous dosing with once-daily administration of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg, serum concentrations of estradiol, estrone, and norethindrone reached steady-state within two weeks with an accumulation of 33 to 47% above concentrations following single dose administration. Unadjusted circulating concentrations of E2, E1, and NET during Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg treatment at steady-state (dosing at time 0) are provided in Figures 1a and 1b.
| Figure 1a: Mean Baseline-Uncorrected Estradiol and Estrone Serum Concentration-Time Profiles Following Multiple Doses of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg (N=24) |
| Figure 1b: Mean Baseline-Uncorrected Norethindrone Serum Concentration-Time Profile Following Multiple Doses of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg (N=24) |
Distribution
Estradiol
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. Estradiol circulates in the blood bound to SHBG (37%) and to albumin (61%), while only approximately 1 to 2% is unbound.
Norethindrone Acetate
Norethindrone also binds to a similar extent to SHBG (36%) and to albumin (61%).
Metabolism
Estradiol
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.
Norethindrone Acetate
The most important metabolites of norethindrone are isomers of 5α-dihydro-norethindrone and tetrahydro-norethindrone, which are excreted mainly in the urine as sulfate or glucuronide conjugates.
Excretion
Estradiol
Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates. The half-life of estradiol following single dose administration of Estradiol/Norethindrone Acetate Tablets 1 mg/0.5 mg is 12 to 14 hours.
Norethindrone Acetate
The terminal half-life of norethindrone is about 8 to 11 hours.
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 percent White, 6.8 percent Black, 5.4 percent Hispanic, 3.9 percent Other) are presented in Table 6. These results reflect centrally adjudicated data after an average follow-up of 5.6 years.
| Event | Relative Risk CE/MPA versus Placebo (95% nCI Nominal confidence intervals unadjusted for multiple looks and multiple comparisons. ) | CE/MPA n = 8,506 | Placebo n = 8,102 |
|---|---|---|---|
| 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 percent 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 percent White, 15.1 percent Black, 6.1 percent Hispanic, 3.6 percent Other), after an average follow-up of 7.1 years, are presented in Table 7.
| Event | Relative Risk CE versus Placebo (95% nCI Nominal confidence intervals unadjusted for multiple looks and multiple comparisons. ) | CE n = 5,310 | Placebo n = 5,429 |
|---|---|---|---|
| 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 percent CI, 0.36-1.09)] and overall mortality [HR 0.71 (95 percent CI, 0.46-1.11)].
Vaginal Bleeding
Inform postmenopausal women to report any vaginal bleeding to their healthcare provider as soon as possible [see Warnings and Precautions (5.2)].
Possible Serious Adverse Reactions with Estrogen Plus Progestogen Therapy
Inform postmenopausal women of possible serious adverse reactions of estrogen plus progestogen therapy including Cardiovascular Disorders, Malignant Neoplasms, and Probable Dementia [see Warnings and Precautions (5.1, 5.2, 5.3)].
Possible Common Adverse Reactions with Estrogen Plus Progestogen Therapy
Inform postmenopausal women of possible less serious but common adverse reactions of estrogen plus progestogen therapy such as headache, breast pain and tenderness, nausea and vomiting.
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Distributed by:
Breckenridge Pharmaceutical, Inc.
Berkeley Heights, NJ 07922
Manufactured by:
Pharmaceutics International, Inc.
Hunt Valley, MD 21031