Femring estradiol acetate .05 mg/d Ring
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the Radioactive Diagnostic Agent class.
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🏭 Manufacturer & labeler
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🩺 Clinical
- Estradiol is a form of estrogen — the main female sex hormone. When estrogen levels fall after menopause (or due to other conditions like ovarian failure), you can get symptoms lik...
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Patient education
Supplement & herbal interactions
Estradiol may be associated with lower levels of 5 nutrients — worth a chat with your pharmacist, not a cause for alarm.
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
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UNII 25BB7EKE2E
Barium sulfate is a white powder mineral compound used as a filler and opacifying agent in tablets and capsules. It adds bulk to the medicine and may be included in formulations for imaging purposes.
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UNII 2RF6EJ0M85
Diatomaceous earth is a fine powder made from fossilized remains of diatoms, tiny aquatic organisms. It acts as a glidant and anti-caking agent, helping medicine flow smoothly during manufacturing and preventing clumping in the final product.
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UNII 92RU3N3Y1O
Dimethicone is a silicone-based oil that acts as an anti-foaming agent and lubricant in medicines. It reduces gas bubbles in liquid formulations and helps coat and protect the stomach lining when ingested.
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UNII 519A78R12Y
A tin-based chemical compound used as a stabilizer and antioxidant in pharmaceutical formulations. It helps prevent degradation of active ingredients and maintains product stability during storage.
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UNII 4PE821G3GH
A silica-based compound used in pharmaceuticals as a binder and flow agent. It helps hold tablet or capsule ingredients together and improves powder flow during manufacturing.
5 inactive ingredients listed in the exact product block matched to this NDC.
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ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per ea | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | $867.928 | $78,113.52 / 90 ds |
| Medicaid paysCMS SDUD · 12 mo | $788.90 | $71,001.04 / 90 ds |
| Medicare drug plans payPart D · Q2 2026 | $862.27 | $77,604.13 / 90 ds |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Femring .05 mg/dthis 72495-0201-05 | Millicent | 1 pouch | $867.928 | — | Availability likely | — |
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⏳ Availability & generic status
We did not find an FDA-approved generic match for this exact strength, form and route.
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🗺️ Medicaid utilization & spend
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 72495-0201-05 You're viewing this | 1 POUCH in 1 CARTON (72495-201-05) / 90 d in 1 POUCH | 2018-12-10 | Active |
📄 Full prescribing information FDA SPL
🚨 Boxed Warning ▾
WARNING: ENDOMETRIAL CANCER, CARDIOVASCULAR DISORDERS, BREAST CANCER AND PROBABLE DEMENTIA 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 (14.3 , 14.4 )] . The Women’s Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral conjugated estrogens (CE) [0.625 mg]-alone, relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.3) ].
The WHI Memory Study (WHIMS) estrogen-alone ancillary study of the WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 5.2 years of treatment with daily 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 (14.4) ]. 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. 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 (14.3 , 14.4 )] . The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism (PE), stroke and myocardial infarction (MI) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral CE (0.625 mg) combined with medroxyprogesterone acetate (MPA) [2.5 mg], relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.3) ] .
The WHIMS estrogen plus progestin ancillary study of the WHI reported 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 (14.4) ] . Breast Cancer The WHI estrogen plus progestin substudy also demonstrated an increased risk of invasive breast cancer [see Warnings and Precautions (5.3) , and Clinical Studies (14.3) ].
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. WARNING: ENDOMETRIAL CANCER, CARDIOVASCULAR DISORDERS, BREAST CANCER, AND PROBABLE DEMENTIA See full prescribing information for complete boxed warning.
Estrogen-Alone Therapy • There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens ( 5.2 ) • Estrogen-alone therapy should not be used for…
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE Femring is an estrogen indicated for: • Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause ( 1.1 ) • Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause ( 1.2 )
1.1Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause.
1.2Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause.
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION Generally, when estrogen is prescribed for a postmenopausal woman with a uterus, a progestin should also be considered to reduce the risk of endometrial cancer. A woman without a uterus does not need a progestin. In some cases, however, hysterectomized women with a history of endometriosis may need a progestin [see Warnings and Precautions (5.2 , 5.14 )].
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. • One ring inserted into the vagina for 3 months. Patients should be started at the lowest dose.
( 2.1 , 2.2 )
2.1Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause Start therapy with 0.05 mg/day. Dosage adjustment should be guided by the clinical response. Therapy should be started at the lowest effective dose and the shortest duration consistent with treatment goals. Attempts to taper or discontinue the medication should be made at 3 to 6 month intervals.
2.2Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause. Start therapy with 0.05 mg/day. Dosage adjustment should be guided by the clinical response. Therapy should be started at the lowest effective dose and the shortest duration consistent with treatment goals. Attempts to taper or discontinue the medication should be made at 3 to 6 month intervals.
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS The following two strengths of Femring are available: Femring (0.05 mg/day): Each off-white, soft, flexible ring has a central core that contains 12.4 mg of estradiol acetate, which releases at a rate equivalent to 0.05 mg of estradiol per day for 3 months. Femring (0.10 mg/day): Each off-white, soft, flexible ring has a central core that contains 24.8 mg of estradiol acetate, which releases at a rate equivalent to 0.10 mg of estradiol per day for 3 months. • Femring (0.05 mg/day): Each off-white, soft, flexible ring has a central core that contains 12.4 mg of estradiol acetate, which releases at a rate equivalent to 0.05 mg of estradiol per day for 3 months.
( 3 ) • Femring (0.10 mg/day): Each off-white, soft, flexible ring has a central core that contains 24.8 mg of estradiol acetate, which releases at a rate equivalent to 0.10 mg of estradiol per day for 3 months. ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS Femring is contraindicated in women with any of the following conditions: • Undiagnosed abnormal genital bleeding • Known, suspected, or history of breast cancer • Known or suspected estrogen-dependent neoplasia • Active DVT, PE, or history of these conditions • Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions • Known anaphylactic reaction or angioedema to Femring • Known liver impairment or disease • Known protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders • Known or suspected pregnancy • Undiagnosed abnormal genital bleeding ( 4 ) • Known, suspected, or history of breast cancer ( 4 , 5.2 ) • Known or suspected estrogen-dependent neoplasia ( 4 , 5.2 ) • Active DVT, PE, or history of these conditions ( 4 , 5.1 ) • Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions ( 4 , 5.1 ) • Known anaphylactic reaction or angioedema to Femring ( 4 ) • Known liver impairment or disease ( 4 , 5.10 ) • Known protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders ( 4 ) • Known or suspected pregnancy ( 4 , 8.1 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS Femring is used only in the vagina, however, the risks associated with oral estrogens should be taken into account. • 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 , 5.18 )
5.1Cardiovascular Disorders An increased risk of stroke and DVT has been reported with estrogen-alone therapy. An increased risk of PE, DVT, stroke, and MI has been reported with estrogen plus progestin therapy. Should any of these occur or be suspected, estrogen with or without progestin therapy should be discontinued immediately.
Risk factors for arterial vascular disease (for example, hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (VTE) (for example, personal history or family history of VTE, obesity, and systemic lupus erythematosus) should be managed appropriately. Stroke In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving 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 (14.3) ] . Should a stroke occur or be suspected, estrogen-alone therapy should be discontinued immediately. Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving CE (0.625 mg)-alone versus those receiving placebo (18 versus 21 per 10,000 women-years).
1 In the WHI estrogen plus progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women in the same age group receiving placebo (33 versus 25 per 10,000 women-years) [see Clinical Studies (14.3) ] . The increase in risk was demonstrated after the first year and persisted. 1 Should a stroke occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.
Coronary Heart Disease In the WHI estrogen-alone substudy, no overall effect on coronary heart disease (CHD) events (defined as nonfatal MI, silent MI, or CHD death) was reported in women receiving estrogen-alone compared to placebo 2 [see Clinical Studies (14.3) ]. Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE [0.625 mg]-alone compared to placebo) in women with less than 10 years since menopause (8 versus 16 per 10,000 woman-years). 1 In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of CHD events reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (41 versus 34 per 10,000 women-years).
1 An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5 [see Clinical Studies (14.3) ]. In postmenopausal women with documented heart disease (n = 2,763, average 66.7 years of age), in a controlled clinical trial of secondary prevention of cardiovascular disease (Heart and Estrogen/Progestin Replacement Study; HERS) treatment with daily CE (0.625 mg) plus MPA (2.5 mg) demonstrated no cardiovascular benefit. During an average follow-up of 4.1 years, treatment with CE plus MPA did not reduce the overall rate of CHD events in postmenopausal women with established 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 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 additi…
🤒 Adverse Reactions ▾
6 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) ]. Most common adverse reactions (incidence > 5 percent) are vaginal bleeding and breast tenderness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Millicent at 1-877-810-2101 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials 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 13-week clinical trial that included 225 postmenopausal women treated with Femring and 108 women treated with placebo vaginal rings, adverse reactions that occurred at a rate of ≥ 2 percent are summarized in Table 1 . Table 1.
Incidence of Adverse Reactions Occurring in ≥ 2 Percent of Subjects Presented in Descending Frequency of Preferred Term AE = adverse event; NOS = not otherwise specified Adverse Event Placebo (n = 108) Estradiol 0.05 mg/day (n = 113) Estradiol 0.10 mg/day (n = 112) n (percent) n (percent) n (percent) Headache (NOS) 10 (9.3) 8 (7.1) 11 (9.8) Intermenstrual Bleeding 2 (1.9) 9 (8.0) 11 (9.8) Vaginal Candidiasis 3 (2.8) 7 (6.2) 12 (10.7) Breast Tenderness 2 (1.9) 7 (6.2) 12 (10.7) Back Pain 4 (3.7) 7 (6.2) 4 (3.6) Abdominal Distension 3 (2.8) 8 (7.1) 3 (2.7) Sinusitis (NOS) 2 (1.9) 2 (1.8) 4 (3.6) Uterine Pain 1 (0.9) 2 (1.8) 5 (4.5) Urinary Tract Infection (NOS) 2 (1.9) 1 (0.9) 4 (3.6)
6.2Postmarketing Experience 1. A few cases of toxic shock syndrome (TSS) have been reported in women using vaginal rings. TSS is a rare, but serious disease that may cause death.
Warning signs of TSS include fever, nausea, vomiting, diarrhea, muscle pain, dizziness, faintness, or a sunburn-rash on face and body. 2. Cases of ring adherence to the vaginal or bladder wall, making ring removal difficult, have been reported in women using vaginal rings and may require surgical removal of the device.
Women should be carefully evaluated for vaginal or bladder wall ulceration or erosion. Cases of vaginal erosion and vaginal ulceration have been reported with other estradiol vaginal rings. If an ulceration or erosion has occurred, consideration should be given to leaving the ring out and not replacing it until healing is complete to prevent the ring from adhering to the vaginal tissue.
3. A few cases of bowel obstruction associated with vaginal ring use have been reported. Persistent abdominal complaints consistent with obstruction should be carefully evaluated.
4. A few cases of inadvertent ring insertion into the urinary bladder, which may require surgical removal, have been reported for women using vaginal rings. Persistent unexplained urinary symptoms should be carefully evaluated.
The following additional adverse reactions have been identified during post-approval use of Femring. 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 Uterine cancer, vaginal hemorrhage, ovarian cyst, irregular menstruation, metrorrhagia, menorrhagia, dysmenorrhea, uterine enlargement.
Breasts Breast cancer, fibrocystic breast disease, breast disorder, breast mass, breast enlargement, breast pain, nipple pain, breast discharge. Cardiovascular Chest pain, increased blood pressure, irregular heart rate, pulmonary embolism, cerebrovascular accident (stroke), hemiparesis, transient ischemic attack, thrombosis. Gastrointestinal Abdominal pain, pancreatitis, cholecystitis, cholelithiasis, vomiting.
Skin Generalized erythema, erythema multiforme, erythema nodosum, rash, hirsutism, pruritis. Eyes Blindness, contac…
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS No drug interaction studies have been conducted for Femring. • Inducers and/or inhibitors of CYP3A4 may affect estrogen drug metabolism ( 7.1 )
7.1Metabolic 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 decrease the plasma concentration 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 the plasma concentration of estrogens and may result in side effects.
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS • Nursing Mothers: Estrogen administration to nursing women has been shown to decrease the quantity and quality of breast milk ( 8.3 ) • 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 )
8.1Pregnancy Femring should not be used during pregnancy [see Contraindications (4) ] . There appears to be little or no increased risk of birth defects in children born to women who have used estrogens and progestins as an oral contraceptive inadvertently during early pregnancy.
8.3Nursing Mothers Femring should not be used during lactation. Estrogen administration to nursing women has been shown to decrease the quantity and quality of the breast milk. Detectable amounts of estrogens have been identified in the breast milk of women receiving estrogen-alone therapy. Caution should be exercised when Femring is administered to a nursing woman.
8.4Pediatric Use Femring is not indicated in children. Clinical studies have not been conducted in the pediatric population.
8.5Geriatric Use There have not been sufficient numbers of geriatric women involved in clinical studies utilizing Femring to determine whether those over 65 years of age differ from younger subjects in their response to Femring. The Women’s Health Initiative Studies 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 (14.2) ]. 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 (14.2) ] .
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-alone or estrogen plus progestin when compared to placebo [see Warnings and Precautions (5.3) , and Clinical Studies (14.4) ] . 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 (14.4) ] .
8.6Renal Impairment The effect of renal impairment on the pharmacokinetics of Femring has not been studied.
8.7Hepatic Impairment The effect of hepatic impairment on the pharmacokinetics of Femring has not been studied.
🤰 Pregnancy ▾
8.1Pregnancy Femring should not be used during pregnancy [see Contraindications (4) ] . There appears to be little or no increased risk of birth defects in children born to women who have used estrogens and progestins as an oral contraceptive inadvertently during early pregnancy.
🧒 Pediatric Use ▾
8.4Pediatric Use Femring is not indicated in children. Clinical studies have not been conducted in the pediatric population.
🧓 Geriatric Use ▾
8.5Geriatric Use There have not been sufficient numbers of geriatric women involved in clinical studies utilizing Femring to determine whether those over 65 years of age differ from younger subjects in their response to Femring. The Women’s Health Initiative Studies 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 (14.2) ]. 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 (14.2) ] .
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-alone or estrogen plus progestin when compared to placebo [see Warnings and Precautions (5.3) , and Clinical Studies (14.4) ] . 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 (14.4) ] .
🆘 Overdosage ▾
10 OVERDOSAGE Overdosage of estrogen may cause nausea, vomiting, breast tenderness, dizziness, abdominal pain, drowsiness and fatigue, and withdrawal bleeding may occur in women. Treatment of overdose consists of discontinuation of Femring with institution of appropriate symptomatic care.
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism 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 hormones seen in postmenopausal women.
12.2Pharmacodynamics There are no pharmacodynamic data for Femring.
12.3Pharmacokinetics Absorption Estradiol acetate is hydrolyzed to estradiol which is absorbed through the vaginal mucosa as evidenced by the mean time to maximum concentration (t max ) for estradiol of about 1 hour (range 0.25 to 1.5 hrs). After achieving the Cmax the estradiol concentration starts declining during the first 24 to 48 hours and then at a relatively constant rate for the remainder of the 3-month dosing interval (see Figure 1 for results from rings stored for 16 months). In vitro studies have shown that this initial release is higher as the rings age upon storage.
Figure 1. Mean serum estradiol concentrations following multiple dose administration of Femring (0.05 mg/day estradiol) (second dose administered at 13 weeks) (inset: mean (±SD) of serum concentration-time profile for dose 1 from 0-24 hours) Following administration of Femring (0.05 mg/day estradiol), average serum estradiol concentration was 40.6 pg/mL; the corresponding apparent in vivo estradiol delivery rate was 0.052 mg/day. Following administration of Femring (0.10 mg/day estradiol), average serum estradiol concentration was 76 pg/mL; apparent in vivo delivery rate was 0.097 mg/day.
Results are summarized in Table 2 below. Table 2. Summary of Mean (Percent RSD)* Pharmacokinetic Parameters for Femring Dose (as estradiol) Number of subjects C max (pg/mL) T max (hour) C avg (pg/mL) Estradiol 1 25 1129 (25) 0.9 (41) 40.6 (26) 0.05 mg/day Estrone 1 25 141 (25) 6.2 (84) 35.9 (21) Estrone sulfate 1 25 2365 (44) 9.3 (39) 494.6 (48) Estradiol 2 12 1665 (23) 0.7 (90) -- 4 0.10 mg/day Estradiol 3 11 -- -- 76.0 (24) Estrone 3 11 -- -- 45.7 (25) * Relative Standard Deviation, 1 Study 1, 2 Study 2, 3 Study 3, 4 -- Not determined Consistent with the avoidance of first pass metabolism achieved by vaginal estradiol administration, serum estradiol concentrations were slightly higher than estrone concentrations.
Distribution The distribution of exogenous estrogens is similar to that of endogenous estrogens. Estrogens are widely distributed in the body and are generally found in higher concentrations in the sex hormone target organs. Estrogens circulate in the blood largely bound to SHBG and albumin.
Metabolism Exogenous estrogens are metabolized in the same manner as endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium of metabolic interconversions. These transformations take place mainly in the liver.
Estradiol is converted reversibly to estrone, and both can be converted to estriol, which is a major urinary metabolite. Estrogens also unde…
🧬 Mechanism of Action ▾
12.1Mechanism 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 hormones seen in postmenopausal women.
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING
16.1How Supplied Each Femring (estradiol acetate vaginal ring) is individually packaged in a pouch consisting of one side medical grade paper and the other side polyester/polyethylene laminate. N 72495-201-05 Femring 0.05 mg/day (estradiol acetate vaginal ring) is available in single units. N 72495-202-10 Femring 0.10 mg/day (estradiol acetate vaginal ring) is available in single units.
16.2Storage and Handling Store at 20º C to 25º C (68º F to 77º F); excursions permitted to -20º C to 40º C (-4º F to 104º F). Do not store unpouched. Insert immediately upon removal from the protective pouch.
16.1How Supplied Each Femring (estradiol acetate vaginal ring) is individually packaged in a pouch consisting of one side medical grade paper and the other side polyester/polyethylene laminate. N 72495-201-05 Femring 0.05 mg/day (estradiol acetate vaginal ring) is available in single units. N 72495-202-10 Femring 0.10 mg/day (estradiol acetate vaginal ring) is available in single units.
📦 Storage and Handling ▾
16.2Storage and Handling Store at 20º C to 25º C (68º F to 77º F); excursions permitted to -20º C to 40º C (-4º F to 104º F). Do not store unpouched. Insert immediately upon removal from the protective pouch.
📋 Description ▾
11 DESCRIPTION Femring (estradiol acetate vaginal ring) is an off-white, soft, flexible ring with a central core containing estradiol acetate. Femring is made of cured silicone elastomer composed of dimethyl polysiloxane silanol, silica (diatomaceous earth), normal propyl orthosilicate, stannous octoate; barium sulfate and estradiol acetate. The rings have the following dimensions: outer diameter 56 mm, cross-sectional diameter 7.6 mm, core diameter 2 mm.
Femring is available in two strengths: Femring 0.05 mg/day has a central core that contains 12.4 mg of estradiol acetate, which releases at a rate equivalent to 0.05 mg of estradiol per day for 3 months. Femring 0.10 mg/day has a central core that contains 24.8 mg of estradiol acetate, which releases at a rate equivalent to 0.10 mg of estradiol per day for 3 months. Estradiol acetate is chemically described as estra-1,3,5(10)-triene-3,17β-diol-3-acetate.
The molecular formula of estradiol acetate is C 20 H 26 O 3 and the molecular weight of estradiol acetate is 314.42. The Structural formula of Estradiol acetate is chemically described as estra-1,3,5(10)-triene-3,17b-diol-3-acetate
💬 Information for Patients ▾
17 PATIENT COUNSELING INFORMATION See FDA-approved patient labeling ( Patient Information and Instructions for Use ).
17.1Vaginal Bleeding Inform postmenopausal women of the importance of reporting abnormal vaginal bleeding to their healthcare provider as soon as possible [see Warnings and Precautions (5.2) ] .
17.2Possible Serious Adverse Reactions with Estrogen-Alone Therapy Inform postmenopausal women of possible serious adverse reactions of estrogen-alone therapy including Cardiovascular Disorders, Malignant Neoplasms, and Probable Dementia [see Warnings and Precautions (5.1 , 5.2 , 5.3 )] .
17.3Possible Less Serious but Common Adverse Reactions with Estrogen-Alone Therapy Inform postmenopausal women of possible less serious but common adverse reactions of estrogen-alone therapy such as headache, breast pain and tenderness, nausea and vomiting. Contact with blood may cause discoloration of Femring during use. This does not affect the release of the drug.
Inform postmenopausal women of the importance of reporting abnormal vaginal bleeding to their healthcare provider as soon as possible.