One ESTRING (estradiol vaginal ring) is to be inserted as deeply as possible into the upper one-third of the vaginal vault. The ring is to remain in place continuously for three months, after which it is to be removed and, if appropriate, replaced by a new ring. The need to continue treatment should be assessed at 3 or 6 month intervals. Should the ring be removed or fall out at any time during the 90-day treatment period, the ring should be rinsed in lukewarm water and re-inserted by the patient, or, if necessary, by a physician or nurse. Retention of the ring for greater than 90 days does not represent overdosage but will result in progressively greater underdosage with the attendant risk of loss of efficacy and increasing risk of vaginal infections and/or erosions.<br/>Instructions for Use: ESTRING (estradiol vaginal ring) insertion The ring should be pressed into an oval and inserted into the upper third of the vaginal vault. The exact position is not critical. When ESTRING is in place, the patient should not feel anything. If the patient feels discomfort, ESTRING is probably not far enough inside. Gently push ESTRING further into the vagina. ESTRING use ESTRING should be left in place continuously for 90 days and then, if continuation of therapy is deemed appropriate, replaced by a new ESTRING. The patient should not feel ESTRING when it is in place and it should not interfere with sexual intercourse. Straining at defecation may make ESTRING move down in the lower part of the vagina. If so, it may be pushed up again with a finger. If ESTRING is expelled totally from the vagina, it should be rinsed in lukewarm water and reinserted by the patient (or doctor/nurse if necessary). ESTRING removal ESTRING may be removed by hooking a finger through the ring and pulling it out. For patient instructions, see Patient Information.
ESTRING' (estradiol vaginal ring) is a slightly opaque ring with a whitish core containing a drug reservoir of 2 mg estradiol. Estradiol, silicone polymers and barium sulfate are combined to form the ring. When placed in the vagina, ESTRING releases estradiol, approximately 7.5 mcg per 24 hours, in a consistent stable manner over 90 days. ESTRING has the following dimensions: outer diameter 55 mm; cross-sectional diameter 9 mm; core diameter 2 mm. One ESTRING should be inserted into the upper third of the vaginal vault, to be worn continuously for three months. Estradiol is chemically described as estra-1,3,5(10)-triene-3,17��-diol. The molecular formula of estradiol is CHOand the structural formula is: The molecular weight of estradiol is 272.39.
Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol, at the receptor level. The primary source of estrogen in normally cycling adult women is the ovarian follicle, which secretes 70 to 500 mcg of estradiol daily, depending on the phase of the menstrual cycle. After menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone by peripheral tissues. Thus, estrone and the sulfate conjugated form, estrone sulfate, are the most abundant circulating estrogens in postmenopausal women. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. To date, two estrogen receptors have been identified. These vary in proportion from tissue to tissue. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.<br/>Pharmacokinetics:<br/>A. Absorption: Estrogens used in therapeutics are well absorbed through the skin, mucous membranes, and the gastrointestinal (GI) tract. The vaginal delivery of estrogens circumvents first-pass metabolism. In a Phase I study of 14 postmenopausal women, the insertion of ESTRING (estradiol vaginal ring) rapidly increased serum estradiol (E) levels. The time to attain peak serum estradiol levels (T) was 0.5 to 1 hour. Peak serum estradiol concentrations post-initial burst declined rapidly over the next 24 hours and were virtually indistinguishable from the baseline mean (range: 5 to 22 pg/mL). Serum levels of estradiol and estrone (E) over the following 12 weeks during which the ring was maintained in the vaginal vault remained relatively unchanged (see Table 1). The initial estradiol peak post-application of the second ring in the same women resulted in ~38 percent lower C, apparently due to reduced systemic absorption via the treated vaginal epithelium. The relative systemic exposure from the initial peak of ESTRING accounted for approximately 4 percent of the total estradiol exposure over the 12-week period. The release of estradiol from ESTRING was demonstrated in a Phase II study of 222 postmenopausal women who inserted up to four rings consecutively at three-month intervals. Systemic delivery of estradiol from ESTRING resulted in mean steady state serum estradiol estimates of 7.8, 7.0, 7.0, 8.1 pg/mL at weeks 12, 24, 36, and 48, respectively. Similar reproducibility is also seen in levels of estrone. The systemic exposure to estradiol and estrone was within the range observed in untreated women after the first eight hours. In postmenopausal women, mean dose of estradiol systemically absorbed unchanged from ESTRING is ~8 percent [95 percent CI: 2.8���12.8 percent] of the daily amount released locally.<br/>B. 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 sex hormone binding globulin (SHBG) and albumin.<br/>C. 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 the 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.<br/>D. Excretion: Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates. Mean percent dose excreted in the 24-hour urine as estradiol, 4 and 12 weeks post-application of ESTRING in a Phase I study was 5 percent and 8 percent, respectively, of the daily released amount.<br/>E. Special Populations: ESTRING has not been studied in patients with hepatic or renal impairment.<br/>F. Drug Interactions: No formal drug interactions studies have been done with ESTRING. In vitro and in vivo studies have shown that systemic estrogens are metabolized partially by cytochrome P450 3A4 (CYP3A4). Therefore, inducers or inhibitors of CYP3A4 may affect estrogen metabolism. Inducers of CYP3A4 such as St. John's Wort preparations (Hypericum perforatum), phenobarbital, carbamazepine, and rifampin may reduce plasma concentrations of estrogens, possibly resulting in a decrease in systemic 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.
Each ESTRING (estradiol vaginal ring) is individually packaged in a heat-sealed rectangular pouch consisting of three layers, from outside to inside: polyester, aluminum foil, and low density polyethylene, respectively. The pouch is provided with a tear-off notch on one side. NDC 0013-2150-36 ESTRING (estradiol vaginal ring) 2 mg - available in single packs.<br/>STORAGE: Store at controlled room temperature 15��to 30��C (59��to 86��F).
WARNINGS:<br/>ENDOMETRIAL CANCER: Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding.<br/>CARDIOVASCULAR AND OTHER RISKS: Estrogens with or without progestins should not be used for the prevention of cardiovascular disease or dementia. 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 6.8 years and 7.1 years, respectively, of treatment with daily oral conjugated estrogens (CE 0.625 mg) relative to placebo. The estrogen plus progestin WHI substudy reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and DVT 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. The Women's Health Initiative Memory Study (WHIMS), a substudy of the WHI, reported 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 and 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 postmenopausalwomen. 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. Because of these risks, 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.
See BOXED WARNINGS, WARNINGS and PRECAUTIONS 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 the two pivotal controlled studies, discontinuation of treatment due to an adverse event was required by 5.4 percent of patients receiving ESTRING and 3.9 percent of patients receiving conjugated estrogens vaginal cream. The most common reasons for withdrawal from ESTRING treatment due to an adverse event were vaginal discomfort and gastrointestinal symptoms. The adverse events reported with a frequency of 3 percent or greater in the two pivotal controlled studies by patients receiving ESTRING or conjugated estrogens vaginal cream are listed in Table 4. Other adverse events (listed alphabetically) occurring at a frequency of 1 to 3 percent in the two pivotal controlled studies by patients receiving ESTRING include: anxiety, bronchitis, chest pain, cystitis, dermatitis, diarrhea, dyspepsia, dysuria, flatulence, gastritis, genital eruption, urogenital pruritus, hemorrhoids, leg edema, migraine, otitis media, skin hypertrophy, syncope, toothache, tooth disorder, urinary incontinence.<br/>Post-Marketing Experience: The following additional adverse events were reported at least once by patients receiving ESTRING in the worldwide clinical program, which includes controlled and uncontrolled studies. A causal relationship with ESTRING has not been established. Body as a Whole: allergic reaction CNS/Peripheral Nervous System: dizziness Gastrointestinal: enlarged abdomen, vomiting Metabolic/Nutritional Disorders: weight decrease or increase Musculoskeletal: arthropathy (including arthrosis) Psychiatric: depression, decreased libido, nervousness Reproductive: breast engorgement, breast enlargement, intermenstrual bleeding, genital edema, vulval disorder Skin/Appendages: pruritus, pruritus ani Urinary: micturition frequency, urethral disorder Vascular: thrombophlebitis Vision: abnormal vision The following additional adverse reactions have been reported with estrogens: Genitourinary system: abnormal uterine bleeding/spotting; dysmenorrheal/pelvic pain; increase in size of uterine leiomyomata; vaginitis, including vaginal candidiasis; change in amount of cervical secretion; changes in cervical ectropion; ovarian cancer; endometrial hyperplasia; endometrial cancer Breasts: 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; abdominal cramps, bloating; cholestatic jaundice; increased incidence of gallbladder disease; pancreatitis, enlargement of hepatic hemangiomas Skin: chloasma or melasma that may persist when drug is discontinued; erythema multiforme; erythema nodosum; hemorrhagic eruption; loss of scalp hair; hirsutism, rash Eyes: retinal vascular thrombosis; intolerance to contact lenses Central Nervous System: headache; migraine; dizziness; mental depression; exacerbation of chorea; nervousness; mood disturbances; irritability; exacerbation of epilepsy, dementia Miscellaneous: increase or decrease in weight; glucose intolerance; aggravation of porphyria; edema; arthralgias; leg cramps; changes in libido; angioedema; anaphylactoid/anaphylactic reactions; hypocalcemia (preexisting condition); exacerbation of asthma; increased triglycerides
ENDOMETRIAL CANCER: Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding.<br/>CARDIOVASCULAR AND OTHER RISKS: Estrogens with or without progestins should not be used for the prevention of cardiovascular disease or dementia. 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 6.8 years and 7.1 years, respectively, of treatment with daily oral conjugated estrogens (CE 0.625 mg) relative to placebo. The estrogen plus progestin WHI substudy reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and DVT 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. The Women's Health Initiative Memory Study (WHIMS), a substudy of the WHI, reported 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 and 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 postmenopausalwomen. 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. Because of these risks, 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.
ESTRING (estradiol vaginal ring) is an estrogen indicated for the treatment of moderate to severe urogenital symptoms due to postmenopausal atrophy of the vagina (such as dryness, burning, pruritus and dyspareunia) and/or the lower urinary tract (urinary urgency and dysuria).